Do you want to hide posts that link to certain websites? You can do this with Mastodon Filters:
1. Create a new filter
2. Add domain names of the sites that you don't want to see links to (e.g. example.com), use new keyword for each domain
3. UN-tick box marked "whole word" for each keyword
4. Save filter
If you're not familiar with using filters, there are easy-to-follow step-by-step instructions for creating filters in the guide at:
➡️ https://fedi.tips/filtering-your-timeline-to-hide-posts-on-mastodon

Filtering your Mastodon timeline to automatically hide posts containing certain words, phrases, hashtags, links or emoji | Fedi.Tips – An Unofficial Guide to Mastodon and the Fediverse
An unofficial guide to using Mastodon and the Fediverse
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