Go modules cannot be updated on GoLand IDE

I'm a beginner on golang. Every time I remove the go 1.13, it suddenly goes back again. I'm not sure why. It has something to do with GoLand?

module github.com/Projec/test

require (
    cloud.google.com/go v0.44.3
    github.com/dgrijalva/jwt-go v3.2.0+incompatible // indirect
    github.com/gobuffalo/envy v1.7.1 // indirect
    github.com/helloeave/json v1.11.0
    github.com/labstack/echo v3.3.10+incompatible
    github.com/labstack/gommon v0.2.8 // indirect
    github.com/mailgun/mailgun-go/v3 v3.6.0
    github.com/mattn/go-colorable v0.1.4 // indirect
    github.com/mattn/go-isatty v0.0.9 // indirect
    github.com/metakeule/fmtdate v1.1.2
    github.com/mileusna/useragent v0.0.0-20190129205925-3e331f0949a5
    github.com/murooka/go-diff-image v0.0.0-20171228143924-8c413ad9b24c
    github.com/pkg/errors v0.8.1
    github.com/sergi/go-diff v1.1.0 // indirect
    github.com/valyala/fasttemplate v1.0.1 // indirect
    golang.org/x/crypto v0.0.0-20190829043050-9756ffdc2472
    golang.org/x/net v0.0.0-20190827160401-ba9fcec4b297
    golang.org/x/text v0.3.2
    google.golang.org/api v0.9.0
    google.golang.org/appengine v1.6.2
)

go 1.13

Solution

You are probably using Go 1.13 to develop your application.

In this case, whenever you run a Go command, like go build, go list, go test, go mod tidy and others, the go.mod file will be modified to have some formatting included, and add missing directives, like the Go version that's compatible with that module.

So, go 1.13 is added to the file automatically, not by the IDE. You can reproduce this by running any of the commands that I listed above.