Gotcha, I was able to successfully run juju bootstrap by creating a configuration file called juju-cloud-config.yml with the following contents:
cloudinit-userdata: |
ca-certs:
trusted:
- |
<INSERT CERTIFICATE HERE>
I then ran:
juju bootstrap --bootstrap-series=focal --config=juju-cloud-config.yml --constraints tags=juju maas-one maas-controller
I believe this added the certification to the juju server during the bootstrap process, which allowed it to validate with the MAAS API
Post that helped me with this: