The maximum allowed webhook’s payload size (Content-Length) is 5 MB.
For more information on webhook limits, see Webhook and its limitations - #2 by samliew
Hope this helps! Let me know if there are any further questions or issues.
— @samliew
P.S.: Did you know, the concepts of about 70% of questions asked on this forum are already covered in the Make Academy. Investing some effort into it will save you lots of time and frustration using Make later!