How Do You Stop These Text Messages?

I don't received any messages likes this. You can try to check the site's setting. I think it can block the notifications about it.

Block the number. I do it all the time when spammers send me unsolicited texts or phone calls.

I get them all the time because some idiot keeps using my phone number as hers. (Not just spam offers, mind, I've gotten calls from her doctors' offices and long rambling voice mails left by her friends, too.) Your carrier should have a number that you can forward spam to; that's what I'd do first, followed by blocking the sender's number. If you want to report unwanted text messages to the FTC, you can do that at the provided link. They don't resolve individual complaints but if they're consistently spamming people the FTC may take action against them. Trouble is a lot of these guys use spoofed numbers so they're hard to track. They're obnoxious AF. https://www.consumer.ftc.gov/articles/how-recognize-and-report-spam-text-messages#what%20to%20do

Sometimes you can text STOP and they will stop.

Yes...I guess we all are getting spammed by these

If they are senting this messages to your phone's in-built/pre installed messaging app. Just block the notifications so that these unwanted messages won't bug you. Clear out the unwanted messages when get free time. Only if you are using another messaging app to chat with you people

You can simply block the unwelcome numbers in your messaging settings, it differs a little on phones depending on model and brand so just check how it's done on yours.

You can blacklist or block these messages.