Can not add price to course in ecommerce

Hello everyone I try to add price to a course in ecommerce platform. I’m sure that course_id and course name is match with course_id and course name in lms. But I can not create course in ecommerce. Here is error:

Please help me, what “Product classes” do you have under https://YOUR_ECOMMERCE_URL/admin/catalogue/productclass/?

There should be a Seat, which should have been added by this migration.

@Agrendalath , I already checked and I realize that someone delete it, I recreated and it worked