There are several possible ways:
1. A source channel’s header can be removed with a command
/setting header none

2. A link to a source post in a footer can be removed with a command
/setting link none

3. Any concrete links in a message’s body can be removed for example with a command
/replace @source
This will replace these specific links with an empty string.

4. Any formatted links in a message’s body can be removed with
/replacerx @source

5. Any raw links can be removed with
/replacerx @source (http\/\/:|https:\/\/)([a-zA-Z0-9.\/\?=&]+)

6. To remove only links containing t.me use
/replacerx @source (t.me)([a-zA-Z0-9.\/\?=&]+)
This will replace all the with an empty string.

7. To remove all links-usernames like @username
/replacerx @source @([a-zA-Z0-9=&]+)