Versioning Nuget Package with GitVersion.yml in Azure Devops

I'm stucking with this for a whole week and I didn't reach where i wanted. I'm thinking about having two branches:

-master

-release(we are calling it vNext - the whole company knows it by this name)

Master branch will generate the packages without prerelease tag. Release will generate the pre release version like:

=>master is on 1.0.0

=>Create a vNext(release) branch like: vNext/1.1.0

=> Code things needed here and commit;

=> Automatically my pipeline is triggered, because I've set the trigger to branch master, vNext or vNext/*

=> I want this to create a package like (1.1.0-beta1)

=>Create a pullRequest to master

=> Automatically my pipeline is triggered,

=> I want this to create a package like (1.1.0)

This is my gitVersion.yml

next-version: 1.0
mode: Mainline
legacy-semver-padding: 0
build-metadata-padding: 0
commits-since-version-source-padding: 0
assembly-versioning-scheme: MajorMinorPatch
assembly-file-versioning-scheme: MajorMinorPatchTag
assembly-informational-format: '{LegacySemVer}'
branches:
  master:
    regex: master
    increment: Patch
    prevent-increment-of-merged-branch-version: true
    tag: ''
    track-merge-target: false
    tracks-release-branches: false
    is-release-branch: false
  release:
    regex: vNext?[/-]
    source-branches: ['master']
    increment: Patch
    prevent-increment-of-merged-branch-version: true
    tag: beta
    track-merge-target: false
    tracks-release-branches: false
    is-release-branch:  true

I can't get this working fine. To reach where I'm now, I've already googled a lot even here in stackoverflow, but couldn't found a solution that fits in the scenario I need.