Problem with Push, how to solve?

Question

go

I used the deployment instructions from Heroku, I also looked for a solution to the problem on the forums, everything was past.
When writing, I get the following error:

remote: note: module requires Go 1.13
remote:  !     Push rejected, failed to compile Go app.
remote: 
remote:  !     Push failed
remote: Verifying deploy...
remote: 
remote: !	Push rejected to m-rp0assistant.
remote: 
To https://git.heroku.com/m-rp0assistant.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/************'
</blockquote>

Ну а вот весь лог пуша:
<blockquote>Enumerating objects: 5, done.
Counting objects: 100% (5/5), done.
Delta compression using up to 4 threads
Compressing objects: 100% (5/5), done.
Writing objects: 100% (5/5), 1.97 KiB | 1007.00 KiB/s, done.
Total 5 (delta 0), reused 0 (delta 0), pack-reused 0
remote: Compressing source files... done.
remote: Building source:
remote: 
remote: -----> Building on the Heroku-20 stack
remote: -----> Determining which buildpack to use for this app
remote: -----> Go app detected
remote: -----> Fetching jq... done
remote: -----> Fetching stdlib.sh.v8... done
remote: -----> 
remote:        Detected go modules via go.mod
remote: -----> 
remote:        Detected Module Name: conf-helper
remote: -----> 
remote:  !!    The go.mod file for this project does not specify a Go version
remote:  !!    
remote:  !!    Defaulting to go1.12.17
remote:  !!    
remote:  !!    For more details see: https://devcenter.heroku.com/articles/go-apps-with-modules#build-configuration
remote:  !!    
remote: -----> New Go Version, clearing old cache
remote: -----> Installing go1.12.17
remote: -----> Fetching go1.12.17.linux-amd64.tar.gz... done
remote: -----> Determining packages to install
remote:        
remote:        Detected the following main packages to install:
remote:        		conf-helper
remote:        
remote: -----> Running: go install -v -tags heroku conf-helper 
remote: github.com/SevereCloud/vksdk/v2
remote: golang.org/x/text/encoding/internal/identifier
remote: golang.org/x/text/transform
remote: github.com/SevereCloud/vksdk/v2/object
remote: golang.org/x/text/encoding
remote: golang.org/x/text/encoding/internal
remote: golang.org/x/text/encoding/charmap
remote: golang.org/x/text/runes
remote: github.com/SevereCloud/vksdk/v2/internal
remote: github.com/SevereCloud/vksdk/v2/events
remote: github.com/SevereCloud/vksdk/v2/api
remote: # github.com/SevereCloud/vksdk/v2/api
remote: ../codon/tmp/cache/go-path/pkg/mod/github.com/!severe!cloud/vksdk/[email protected]/api/api.go:241:15: undefined: http.NewRequestWithContext
remote: ../codon/tmp/cache/go-path/pkg/mod/github.com/!severe!cloud/vksdk/[email protected]/api/errors.go:846:5: undefined: errors.As
remote: ../codon/tmp/cache/go-path/pkg/mod/github.com/!severe!cloud/vksdk/[email protected]/api/errors.go:851:5: undefined: errors.As
remote: ../codon/tmp/cache/go-path/pkg/mod/github.com/!severe!cloud/vksdk/[email protected]/api/errors.go:917:5: undefined: errors.As
remote: ../codon/tmp/cache/go-path/pkg/mod/github.com/!severe!cloud/vksdk/[email protected]/api/errors.go:922:5: undefined: errors.As
remote: note: module requires Go 1.13
remote:  !     Push rejected, failed to compile Go app.
remote: 
remote:  !     Push failed
remote: Verifying deploy...
remote: 
remote: !	Push rejected to m-rp0assistant.
remote: 
To https://git.heroku.com/m-rp0assistant.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/*********'

Answer 1

In go.mod it was necessary to add:

// +heroku goVersion go1.15

Read more here!

Answer 2

Do you have a go.mod file in your project?
If not, create it properly.
If so, check what version of go is listed there and specify 1.15