Answers for "301 redirect old domain to new domain all pages"

301 redirect subdomain to domain

RewriteEngine On
RewriteBase /
RewriteRule ^(.*)$ http://domain2.com/$1 [L,R=301,NC]

how to create a 301 redirect with domain.com

RewriteEngine On 
RewriteCond %{HTTP_HOST} ^DOMAIN.com [NC]
RewriteCond %{SERVER_PORT} 80 
RewriteRule ^(.*)$ https://www.DOMAIN.com/$1 [R=301,L]