In Salesforce Marketing Cloud Engagement (aka SFMC or MCE), run the below as a script activity in automation studio. The activity is meant to update file names within the data extract activity.

Update_DataExtract.ssjs

/* ************************************************************************
Unable to find specific documentation for the endpoint. Listing these references instead:

Supported Operations for Objects and Methods (SOAP API)
https://developer.salesforce.com/docs/marketing/marketing-cloud/guide/supported_operations_for_objects_and_methods.html

DataExtractActivity (SOAP API Object)
https://developer.salesforce.com/docs/marketing/marketing-cloud/guide/dataextractactivity.html

Create via WSProxy (giving similar endpoint, but for POST)
https://developer.salesforce.com/docs/marketing/marketing-cloud/guide/ssjs_WSProxy_create.html?q=automation%2Fv1%2Fdataextracts#example-create-and-start-a-data-extract

Stack Exchange Reference
https://salesforce.stackexchange.com/questions/370272/unable-to-update-data-extract-activity-via-automation-v1-dataextracts-dataext
************************************************************************ */
<script runat="server">
    Platform.Load("Core","1");
    var payload = {
    "grant_type": "client_credentials",
    "client_id": "XXXX", // found in Setup > Platform Tools > Apps > Installed Packages
    "client_secret": "XXXX" // found in Setup > Platform Tools > Apps > Installed Packages
};
var tenantSubdomain = "XXXX" // found in Setup > Platform Tools > Apps > Installed Packages
var authurl = "https://" + tenantSubdomain + ".auth.marketingcloudapis.com/v2/token";
var result = HTTP.Post(authurl, 'application/json', Stringify(payload));
  
if (result.StatusCode == 200) {
    var responseJson = Platform.Function.ParseJSON(result.Response[0]);
    var accessToken = responseJson.access_token;
    var restUrl = responseJson.rest_instance_url;
    Variable.SetValue("@accessTokenFinal", accessToken);

        var accessTokenFinal = accessToken;
        var dataExtractOneObjectId = "XXXX"; // found in url of the activity
        var dataExtractOneTypeId = "XXXX"; // found in picklist within the activity
        var dataExtractTwoObjectId = "XXXX"; // found in url of the activity
        var dataExtractTwoTypeId = "XXXX"; // found in picklist within the activity
        var fileTransferObjectId = "XXXX"; // found in url of the activity
        var fileTransferLocationId = "XXXX"; // found in picklist within the activity
        var setFileNameToday = Format(Now(), 'yyyyMMdd');
        var yesterday = new Date();
        yesterday.setDate(yesterday.getDate() - 1);
        var setYesterday = yesterday.getFullYear() + ('0' + (yesterday.getMonth() + 1)).slice(-2) + ('0' + yesterday.getDate()).slice(-2);
        var setZipFileNamePreviousDay = "statictext_" + setYesterday + ".zip";
        var setCsvFileName = "differentstatictext_" + setYesterday + "_" + setFileNameToday + ".csv";
    
        var restapi_url_dataextractactivityOne = "https://" + tenantSubdomain + ".rest.marketingcloudapis.com/automation/v1/dataextracts/" + dataExtractOneObjectId;
        
        var restapi_payloadOne = "{\"dataExtractTypeId\": \"" + dataExtractOneTypeId + "\", \"intervalType\": 1, \"fileSpec\": \"" + setCsvFileName + "\"}";
        
        var headerNames = ["Authorization"]; 
        var s1="Bearer ";
        var headerValues = "Bearer " + accessToken;
        
        var reqdeaOne = new Script.Util.HttpRequest(restapi_url_dataextractactivityOne);
        reqdeaOne.contentType = "application/json"
        reqdeaOne.setHeader("Authorization", headerValues);
        reqdeaOne.method = "PATCH"; 
        reqdeaOne.postData = restapi_payloadOne;
        var restapi_result = reqdeaOne.send();
        
        var restapi_url_dataextractactivityTwo = "https://" + tenantSubdomain + ".rest.marketingcloudapis.com/automation/v1/dataextracts/" + dataExtractTwoObjectId;
        
        var restapi_payloadTwo = "{\"dataExtractTypeId\": \"" + dataExtractTwoTypeId + "\", \"intervalType\": 0, \"fileSpec\": \"" + setZipFileNamePreviousDay + "\", \"dataFields\": [{\"name\": \"ArchiveFolder\", \"type\": \"string\", \"value\": \"\"}, {\"name\": \"DeleteFiles\", \"type\": \"bool\", \"value\": \"False\"}, {\"name\": \"FileFilter\", \"type\": \"string\", \"value\": \"" + setCsvFileName + "\"}, {\"name\": \"ImportFolder\", \"type\": \"string\", \"value\": \"Import\"}, {\"name\": \"OutputFolder\", \"type\": \"string\", \"value\": \"Import\"}]}";
        
        var headerNames = ["Authorization"]; 
        var s1="Bearer ";
        var headerValues = "Bearer " + accessToken;
        
        var reqdeaTwo = new Script.Util.HttpRequest(restapi_url_dataextractactivityTwo);
        reqdeaTwo.contentType = "application/json"
        reqdeaTwo.setHeader("Authorization", headerValues);
        reqdeaTwo.method = "PATCH"; 
        reqdeaTwo.postData = restapi_payloadTwo;
        var restapi_result = reqdeaTwo.send();
        
        var restapi_url_filetransfer = "https://" + tenantSubdomain + ".rest.marketingcloudapis.com/automation/v1/filetransfers/" + fileTransferObjectId;
        
        var restapi_payload = '{"id": "' + fileTransferObjectId + '", "fileTransferLocationId": "' + fileTransferLocationId + '", "fileSpec": "' + setZipFileNamePreviousDay + '"}';
        
        var headerNames = ["Authorization"]; 
        var s1="Bearer ";
        var headerValues = "Bearer " + accessToken;
        
        var reqft = new Script.Util.HttpRequest(restapi_url_filetransfer);
        reqft.contentType = "application/json"
        reqft.setHeader("Authorization", headerValues);
        reqft.method = "PATCH"; 
        reqft.postData = restapi_payload;
        var restapi_result = reqft.send();
    
} else {
    throw new Error("Error: No access token.");
}
</script>