It seems from earlier comments in this thread that they do allow it on a VPS.
My other hosting it was 2 clicks to install LetsEncrypt! HostGator just don’t want to do it.
I’ll admit - I’m pretty disappointed with HG right now - in addition to this moneygrab (yeah I get they are a business) but they decided out of the blue this weekend to add a Caching Plugin to the must-use section of all my wordpress sites. They are not a customer friendly company.
I am beginning to see why a consultant I work with is no longer recommending HG to their clients. It’s a shame - they used to be a great company. It will be interesting to see how they respond when WP makes SSL mandatory as reported later this year.