You will need your namecheap username, API KEY (https://www.namecheap.com/support/api/intro.aspx) and your external IP address (or an URL to get it), this IP will need to be whitelisted at Namecheap.
Due to Namecheap's AP limitation all the records of your domain will be read and re applied, make sure to have a backup of your records you could apply if any issue would arise.
```sh
export NAMECHEAP_USERNAME="..."
export NAMECHEAP_API_KEY="..."
export NAMECHEAP_SOURCEIP="..."
```
NAMECHEAP_SOURCEIP can either be an IP address (e.g. 145.34.23.54) or an URL to provide it (e.g. https://ifconfig.co/ip).
The username and password will be saved in `~/.acme.sh/account.conf` and will be reused when needed.