Multiple IP and multiple certificate

On debian running Globaleaks I have three different IPs pointing to three different public IPs.
I would like to register three separate certificates for my three “sites”, but I can only configure the one with the first IP.
I suspect that the software does not try to exit with all three public IPs to attempt automatic registration with let’s encrypt, but only with one IP.
Is there any way to indicate, based on the site, on which IP to attempt certificate registration?