Magento 2 checkout bad request

For the past 2 days, I haven’t had any sales because Magento checkout is not processing my orders. It’s giving me this error: “An error occurred on the server.”

Error 400 While Receiving The Response From Payment Information.

Image error:
https://scontent.fgdl2-1.fna.fbcdn.net/v/t39.30808-6/350119154_730127159120672_7714966606860123206_n.jpg?_nc_cat=100&ccb=1-7&_nc_sid=5cd70e&_nc_eui2=AeGIQ7qut0H7gWEEgB9N7Mm3q_y6kDPom-6r_LqQM-ib7mb0NDVjXdmecKYS4jdqmjw&_nc_ohc=543G_33ZIqwAX-LcVCn&_nc_ht=scontent.fgdl2-1.fna&oh=00_AfCWOHKtzf-FAxRm1QRwj6qC2hSJ59mdvhfIOb9i7bxr1w&oe=6478A642

Has anyone experienced this issue before and knows how to resolve it, or has any ideas on how I could find a solution?

Thank you very much.