webcrypto-rsa.mjs

const name = 'RSA-OAEP';
const hash = 'SHA-256';
const modulusLength = 2048;
const publicExponent = new Uint8Array([1, 0, 1]);
const format = 'spki';
const message = 'hello';

// browser
const { privateKey, publicKey } = await crypto.subtle.generateKey(
  { name, hash, modulusLength, publicExponent },
  true,
  ['decrypt']
);

// browser
const exportedPublicKey = await crypto.subtle.exportKey(format, publicKey);

// node
const importedPublicKey = await crypto.subtle.importKey(
  format,
  exportedPublicKey,
  { name, hash },
  false,
  ['encrypt']
);

// node
const encoded = new TextEncoder().encode(message).buffer;
const encrypted = await crypto.subtle.encrypt(
  { name },
  importedPublicKey,
  encoded
);

// browser
const decrypted = await crypto.subtle.decrypt({ name }, privateKey, encrypted);
const decoded = new TextDecoder().decode(decrypted);

console.log(decoded);