Cannot add GitLab public key during installation

Hi all, I’ve spent over an hour trying to solve this so I figured it was time to ask for help.

Just to give some background in case it matters, I have a PC running Windows 10 and installed GitLab so I could host a blog. I had no issues at all with that.

About a month ago, I wanted to try out Ubuntu so installed it as a dual-boot option and so far am loving it. In fact, I found myself rarely booting into Windows any more so I wanted to install GitLab on Ubuntu and use it for working on my blog. Again, not sure if it matters, but I already have Github installed for work and use SSH.

I’ve followed the installation guide but when I get to the part where I need to run the following command:

sudo apt install gitlab-ee

I get the following output:

Reading package lists... Done
Building dependency tree    
Reading state information... Done
E: Unable to locate package gitlab-ee

I thought that the repository needed to be updated so ran sudo apt update but received the following:

Get:8 https://packages.gitlab.com/gitlab/gitlab-ee/ubuntu focal InRelease [23.3 kB]
Err:8 https://packages.gitlab.com/gitlab/gitlab-ee/ubuntu focal InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 3F01618A51312F3F
Reading package lists... Done
W: GPG error: https://packages.gitlab.com/gitlab/gitlab-ee/ubuntu focal InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 3F01618A51312F3F
E: The repository 'https://packages.gitlab.com/gitlab/gitlab-ee/ubuntu focal InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

I did some research and it appears that I just need to add the public key but I’ve tried a variety of approaches and the output I always get is as follows:

Executing: /tmp/apt-key-gpghome.9BBxce7cwo/gpg.1.sh --keyserver keyserver.ubuntu.com --recv-keys 3F01618A51312F3F
gpg: key 3F01618A51312F3F: public key "GitLab B.V. (package repository signing key) <packages@gitlab.com>" imported
gpg: Total number processed: 1
gpg:               imported: 1
gpg: invalid key resource URL '/etc/apt/trusted.gpg.d/home:ungoogled_chromium.gpg'
gpg: keyblock resource '(null)': General error
gpg: key 02456C79B2FD48BF: 1 signature not checked due to a missing key
gpg: key 3B4FE6ACC0B21F32: 3 signatures not checked due to missing keys
gpg: key D94AA3F0EFE21092: 3 signatures not checked due to missing keys
gpg: key 871920D1991BC93C: 1 signature not checked due to a missing key
gpg: Total number processed: 8
gpg:       skipped new keys: 8

Anyone happen to have any ideas how to fix this? Does this maybe have something to do with the fact that I have Github installed already?

Any advice/suggestions would be greatly appreciated.

Try this command from the install docs as it should do all that for you:

curl https://packages.gitlab.com/install/repositories/gitlab/gitlab-ee/script.deb.sh | sudo bash