Cannot change custom text anymore

Hi!

A couple of years ago I added a custom text in the ‘customer order is in process’ e-mails, with my adress for sending something after the order. I want to change my adress in this text, but it seems like the whole option to add this text is gone.

Could you please help me?

This is an image of the text I am talking about: https://snipboard.io/lJ6Qnr.jpg

Thank you!

Kind regards,
Sabine

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