Using Mail in a box as a DNS for certbot chalenge

Help with Unusual Circumstances
1

I have been trying to set up a webserver on a subdomain, since I can’t open port 80 on the webserver I can’t use the usual method for provisioning certificates, so I have to use the DNS method
Are there any existing plugins for this?
Would adding a DNS provider for which there is a plugin as a secondary DNS do the trick?

2

This is really a question for the Let’s Encrypt people.

3

As far as I know they have stopped developing official plugins, I also have figured out the answer to the second question, no

4

I have used certbot (let’s encrypt) successfully on my webserver vm.

5

using the Http-01 validation or Dns-01?

6

Using Http-01

Haven’t put the effort for Dns-01