It’s hard to say what is going on here since your repo is private, so I’m shooting in the dark here. Did you try following this excellent guide? Do you have a v2 go.mod file? Did you git tag v2.0.0? I could be wrong but it looks like you might have a v1.1.0 tag but not a v2.
Yes i did have my go.mod of the utility package ie cmdparser having module path v2 appended and also the tags were pushed.
vinu@vinu-HP-Spectre-x360-Convertible-13-ae0xx:~/cmdparser$ git tag -l
v1.0.0
v1.0.1
v1.1.0
v2.0.0
The only thing that fixed the issue is - creating directory as its mentioned in the doc u sent.
I initially used v2 branch and pushed v2.0.0 tag and tried to install using go get github.com/xxxx/cmdparser/v2 for executable module to pick up the latest version.