Your release-tag should be named `M.N.P`.
Note that, unlike the release candidate branch, there is no `rel_` or `v` at the beginning of the tag name.
sh
sensible-browser "https://github.com/rochefort-lab/fissa/releases/new?target=${vMNx}&tag=${MNP}&title=Version%20${MNP}"
**Note:** Be sure to set the target of the tag to your stable release branch `M.N.x`.