He says: Is it prescribed for a person to perform 'umrah and dedicate it to the Prophet?

ﷺ. In terms of being prescribed, it is prescribed, but it is not a sunnah.

And none of the sahaba did it, and they loved the Prophet more than anyone.

Okay, and they did not do it, and Allah had already forgiven the Prophet for his past and future sins, he does not need your 'umrah.

You are the one who needs it, so a person should focus on himself.

What is required from you regarding the Prophet ﷺ is that when he is mentioned, you send prayers upon him—may Allah's ﷺ —and he has already received all our rewards.

Whoever starts a good practice will have its reward and the reward of those who act upon it. Everyone who performs Hajj, everyone who performs Umrah, the Prophet has a share.

ﷺ.