I don’t have the mms option on my iPad Pro 4th generation

An iPad alone cannot send any SMS message, whether that includes MMS or not. When connected to an iPhone, then it uses its cellular connestion to send those messages. The iPad only has Cellular Data and not the Cellular connection for phone calls, which is the same as SMS/MMS.

Lucia1114 wrote:

How do I send a mms message if I don’t have the option to enable it

You need to have an iphone to set this up Continuity features and requirements for Apple devices - Apple Support