GitLab Pages .well-known acme-challenge for wildcard (non-custom) domains using Let's Encrypt

I'm trying to add an SSL wildcard certificate to our GitLab Pages installation using Let's Encrypt, but not for a custom domain so I'm not using the Let's Encrypt integration.

The way I'm doing this is by creating the certificates locally to the upload and use them in our server.

To do so, I'm following certbot instructions which made me:

• Add a DNS TXT record to our DNS provider (done without issues)
• Create the .well-known/acme-challenge file and make the server respond to http://pages.ourdomain.xyz/.well-known/acme-challenge/<token>

The question is, where should I put the file on our on-prem server to let the Pages daemon provide the acme-challenge? 🤔