Look at the situation
Check the exact device model, regional version and provider compatibility. A manufacturer may produce variants with different SIM support. If an employer manages the phone, there may also be restrictions on changing mobile profiles.
Read the conditions
Make sure the account can be accessed without losing the line receiving verification messages. Have stable internet and enough battery. An activation QR is sensitive information and should not be passed to an independent guidance service.
Choose the next question
A failed download and a failed network registration are different symptoms. Write down the error and ask the provider how to recover. Deleting a profile repeatedly can make recovery harder and should not be a routine first step.
Keep official confirmation in view.
All explanations here are general guidance. Use your provider’s current instructions and service documents before taking action.
Official reading routes