Welcome to FT!
Could you be more specific about the error? A simple mistake (wrong letter, missing a letter, forgot middle name etc) will not lead to you being unable to board the flight. I have read somewhere that up to 4 letters can be erroneous in the name without consequences. So most likely no correction is needed.
Disregard the OTA. This is the standard reply of all TA/OTA: cancel and rebook (and of course they earn money from that transaction) rather than the TA/OTA doing the work (correction of name) without getting paid. Forget about taking advice from the OTA about this.