In your Payroll settings in Onfolk, the details in your "Government gateway login" and "Payroll reference numbers" sections are used to identify your business with HMRC for payroll.
If these details are not accepted by HMRC, you will not be able to run payroll or receive HMRC notifications into Onfolk.
You can test if these details are accepted by HMRC by using the "Test PAYE credentials" button in Onfolk.
If you get an error, it could be due to a few different reasons:
A typo in your "Government gateway login" username or password
Your Government gateway password has changed, but hasn't been updated in Onfolk
You are locked out of your Government Gateway portal.
You'll need to resolve this before you can use your credentials for payroll
Your PAYE credentials are not active
When you first register as an employer with HMRC, you receive a letter in the post with a code. That code needs to be entered in your HMRC portal before it expires in order to activate your PAYE credentials.
Once resolved, you can use the "Test PAYE credentials" button once more to verify that your fix has worked.