Here's an example how to set up zone info for bind.
_dmarc.example.com. IN TXT "v=DMARC1; p=quarantine; aspf=r; adkim=r"
rs20240214._domainkey.example.com. IN TXT ("v=DKIM1; k=rsa; p="
"......"
"......"
"......"
"......"
"......")
The knack is how to write down the long pubkey by surrounding () and separete with a space.