Gitlab: You are not allowed to push code to this project

I am very new in Gitlab. For playing a little bit and start learning I have created a project and cloned in my local machine. I have done a change and I have committed it without problems. Now I am trying to push those changes from local to the remote repository in Gitlab.

I use Gitextensions for doing so and I am getting below error (see below screenshot):

I only have a branch in remote, the master and it is not protected. How can I give push permissions from Gitlab in order to I can do the push successfully?

As torek mentioned you should use ssh authentication with Gitlab server.

In Gitlab docs you can find helpful info
How to create an SSH key:
https://docs.gitlab.com/ee/ssh/#generate-an-ssh-key-pair

How to add this key to your Gitlab account:
https://docs.gitlab.com/ee/ssh/#add-an-ssh-key-to-your-gitlab-account