Let's Encrypt mandates usage of the dns-01 challenge for wildcard certificates. See Challenge Types - Let's Encrypt for more info.
The --standalone plugin you're currently using does not support the dns-01 challenge. You should use a DNS plugin for that (see User Guide — Certbot 1.21.0 documentation and/or User Guide — Certbot 1.21.0 documentation) or use the --manual plugin (see User Guide — Certbot 1.21.0 documentation). Note that the manual plugin can be automated using --manual-auth-hook and --manual-cleanup-hook (see User Guide — Certbot 1.21.0 documentation). Automation is obviously highly recommended!
I see your domain is hosted on NameCheap, correct? Certbot itself does not have a DNS plugin for NameCheap, although I did find a third party (not listed in the third party plugin table) with aid of Google: GitHub - schubc/certbot_dns_namecheap: Certbot plugin to provide dns-01 challenge support for namecheap.com. However, that same plugins readme does mention the NameCheap API is only available when a user meets a few conditions such as "have at least 20 domains under your account" and having spent at least $ 50 the last year.. Probably not something a regular user does? That said, that repository hasn't been updated for 3 years now, so perhaps things have changed.. For better (maybe Namecheap has relaxed their API requirements) or for worse (perhapse the plugin doesn't work any longer..)
See Intro to API for Developers | Namecheap.com for more info about the NameCheap API. The requirements above aren't listed there literally, so maybe you're in luck.
Also I noticed that the ACME client acme.sh also has a DNS plugin for NameCheap. Note that acme.sh currently defaults to the ZeroSSL certificate authority and you'll need to use some extra options to use Let's Encrypt.
Edit: that NameCheap plugin for certbot is HELL. Doesn't work on my system. Depends on ancient libraries. Not worth the effort if you'd ask me.