Merging kcalutils release/20.04 onto master

[Glen Ditchfield]

I was asked to commit a small change to kcalutils release/20.04 branch
(a 4-line change to src/templates/todo.html).  I seem to have managed that:
https://invent.kde.org/pim/kcalutils/-/commit/c12e9b37

Now, stepping through https://community.kde.org/Infrastructure/GitLab I am 
trying to merge to master.  I have run these commands:

    $ git checkout master
    $ git pull
    Already up to date.
    $ git merge -s recursive -Xours  remotes/origin/release/20.04                           
    Merge made by the 'recursive' strategy.
     src/templates/todo.html | 4 ++++
     1 file changed, 4 insertions(+)

(At this point my workspace contains what I want:  todo.html has the changes, 
and reassuringly,  CMakeLists.txt does not contain the changes in release/
20.04;  it looks the same as the version in master.)

    $ git push
    FATAL: W any pim/kcalutils gditchfield DENIED by fallthru
    (or you mis-spelled the reponame)
    fatal: Could not read from remote repository.

    Please make sure you have the correct access rights
    and the repository exists.

I think I have access, since I am in the developer group.

What went wrong?

Is there some other way to make the merge?