ERR127 means that Beam does not have a current direct debit authority on file that matches the bank details provided.
To resolve this error, you will need to complete the Beam configuration process again and re-sign the direct debit authority, making sure you proceed all the way to the final step.
Even if you have previously configured Beam and your bank details are correct, the direct debit authority may be missing, expired, or not fully completed, and must be re-signed to create a valid authority in Beam's system.