Let's encrypt addon and Bad Request error

Hi,
Trying to install Let’s Encrypt inside HASSIO (using the addons repository), I can’t make it work because of a weird issue.
When I click “Start” after installing, it seems nothing is happening. But if I look at the Console of Chrome (for example), I see that the page cannot be found :

The URL it tries to launch is : http://xxxxxxxxxx/api/hassio/addons/core_letsencrypt/start

I tried uninstalling, reinstalling, but always getting this error.
Any idea ?
Thanks

Hi,

Was happening because of bad ports configuration. Had HA on port 80 so the port was not free for the addon to work properly.
Followed this guide to make it work : https://smarthomehobby.com/encrypt-home-assistant-with-lets-encrypt/

Regards.