If your DNS record A cpanel is proxied , I’d suggest you to use your hosting sub-domain, e.g. server123.myhosting.com instead.
Otherwise, use an FTP software to connect to the origin, download the file, edit and re-upload.
The behaviour which you’re experiencing is expected since it triggers the Cloudflare WAF Managed Rule to block such requests.
If you’re on a paid plan type, at least Pro plan, you could add an Exception for it to skip for the proxied cpanel DNS record. Otherwise, I am afraid there is no way to except temporary unpausing Cloudflare or switching from to (DNS-only) the particular cpanel hostname for your domain under the DNS tab of Cloudflare dashboard.
There are topics about this case since earlier already: