Re: I can't use TLS1.3 only in my site,please help

TLS 1.3 requires that you specify the following AEAD (Authenticated Encryption with Associated Data) ciphers:

Try remove from nginx configuration ECDHE-ECDSA-CHACHA20 POLY1305:ECDHE+AES128:RSA+AES128:ECDHE+AES256:RSA+AES256:ECDHE+3DES:RSA+3DES

and leve those three:
TLS13-CHACHA20-POLY1305-SHA256
TLS13-AES-256-GCM-SHA384
TLS13-AES-128-GCM-SHA256

You may tweak the order, but you should activate all three of the above.

for more information:
https://www.cloudinsidr.com/content/tls-1-3-and-tls-1-2-cipher-suites-demystified-how-to-pick-your-ciphers-wisely/