My number is showing a different number whenever I send a text message.

Please I need urgent help. I recently moved to Lebara. My number is 07405 991261 but whenever I send text messages, this number 07344901415 shows as the sender.
Can this be corrected?

Sounds like your phone still has old RCS / iMessage details thats not a lebara fault you need to deactivate and reactivate RCS / iMessage its a known issue when porting with all providers