Sure, at least four come to mind:
- Figure out what the docs have to say about using certbot in manual mode, and do that.
- Use something like https://gethttpsforfree.com/ to do the interfacing for you and obtain a certificate.
- If you have control over your DNS records, use one of the alternative clients that support the DNS challenge (I understand all the Bash and Go clients do, and likely others as well).
- Switch to a hosting provider that supports letsencrypt so you can get the cert with a click in your domain control panel.
Edit: but having obtained the certificate, the first three will still require that you have the ability to install it, which you may not have.