SMS Issue Mudi (GL-E750V2)

Hello,

I'm a French user, and in my country some ISPs, like SFR (in this case) are asking to send recharge code to 952, but it seems impossible to do that with Mudi as it throws an error, probably because it expects more digits. Is there anything I can do or fix planned? Currently I have to send the SMS on my phone and then put the sim into the Mudi, which is a bit annoying.

If you are familiar with shell access:
https://openwrt.org/docs/guide-user/advanced/sms-from-shell

Thank you, I will try this.

Is this USSD short code?
What is your firmware version?
Can you send a picture that shows the error?