How can I block porn txt messages

Hello carolin178,

Sorry this is happening. I am very glad you know the danger of unsolicited links. This Apple Support article discusses some options. Unfortunately, it is much easier to screen spam phone calls than text messages. If this is coming from the same number every time you can block that number. If the number changes your best option will be speaking with your phone carrier. I use T-Mobile, they have an app that screens calls (not text) plus allows us to change our number, free of charge, once a year. Call them first tho if you use T-Mobile. There may be other things they, or any carrier, can do before you use the nuclear option.

Block phone numbers, contacts, and emails on your iPhone, iPad, or iPod touch - Apple Support

I don't get a lot of spam text but I have filtering turned on. I don't check the unknown area often so they don't bother me.

"Filter messages from unknown senders

You can filter messages from people who aren't saved in your Contacts.

To filter messages, go to Settings > Messages and turn on Filter Unknown Senders.

n Messages, tap  Filters, then tap Unknown Senders. You won't get notifications for these messages."

I hope this helps.