Please I need a help

[JenniferJero]

First of all, I know nothing about programming and I'm trying to learn about it.

I'm trying to make a bot that sends an sms on a specific date to several people.

So I tried to use custom twilio message.

I paid for twilio and appsheet. I can send an message when I use my own phone number in 'To' field. But when I try to use 'phone number' column in 'to' field it makes an error.

Error encountered in step with name [Send a notification]: Error: No SMS was created because 'To' is missing or invalid

I list all the country code like US, KR. I don't know what to do more. 

When I use my phone number like this, it works.

번호 is phone number

When I try to use column, it makes an error: Error encountered in step with name [Send a notification]: Error: No SMS was created because 'To' is missing or invalid

[Simon_Robinson]

So probably To isn't in the number format its expecting.  Make sure you've got the country set right in appsheet and twilio