Shopify app fails to work on Heroku server

I have a warranty app that doesn't work for some reason.

For example, here I can see these errors in console But when I go in controller I can't see that function there

Can you tell me to find out the meaning of that error and how it can be fixed?

here are some lines from the log:

2022-09-21T14:20:59.707211+00:00 app[web.1]: I, [2022-09-21T14:20:59.707111 #4] INFO -- : [72578400-e157-4979-a567-edd53de799b7] Completed 500 Internal Server Error in 540ms (ActiveRecord: 30.9ms)
2022-09-21T14:20:59.708614+00:00 app[web.1]: F, [2022-09-21T14:20:59.708527 #4] FATAL -- : [72578400-e157-4979-a567-edd53de799b7]
2022-09-21T14:20:59.708658+00:00 app[web.1]: F, [2022-09-21T14:20:59.708618 #4] FATAL -- : [72578400-e157-4979-a567-edd53de799b7] 
2022-09-21T14:20:59.708702+00:00 app[web.1]: F, [2022-09-21T14:20:59.708661 #4] FATAL -- : [72578400-e157-4979-a567-edd53de799b7]
2022-09-21T14:20:59.708726+00:00 app[web.1]: F, [2022-09-21T14:20:59.708699 #4] FATAL -- : [72578400-e157-4979-a567-edd53de799b7] app/controllers/api/v1/warranties_controller.rb:15:in `create'
2022-09-21T14:20:58.448710+00:00 app[web.1]: I, [2022-09-21T14:20:58.448450 #4] INFO -- : [9eab687f-5141-4478-840f-cf2f9144f1cb] Started GET "/app_proxy/?shop=jowissawatches.myshopify.com&logged_in_customer_id=&path_prefix=%2Ftools%2Fproduct-registration&timestamp=1663770058&signature=adcfa0577075ccceac00774f16a7201111314bea1e9793f8dfd489d365da40b8" for 34.147.5.17 at 2022-09-21 14:20:58 +0000