Alcatel SmartFlip2 (4052R) on FreeUp unable to connect to network to make calls

The 4052R is on ATT's list of phones that will work after the 3G retirement. I logged in my FreeUp account and things look OK. The free plan was renewed mid-June and is set to renew again mid-July. I remember using the phone on April (but in a different location because I was away for about 3 months). Now I try to make calls on various places around town and the phone says it can't connect to a network. When I boot the phone it displays a scrolling 'Searching' on the upper left corner; 'FreeUp' used to be displayed there. After a couple minutes of 'Searching', it gives up and 'Searching' becomes 'Emergency Calls Only'.

What do you think? Could something be wrong with my grandfathered free FreeUp account? Could I need to turn on some 4G/LTE/etc settings?

I have two unlocked 4051S (Alcatel GO Flip V)on FreeUp. They don't get a great signal at home but they always work. And they are not on that list.

My 4052R used to work fine at home back in February. Then I had to go away (I used the phone in April) and now the phone can't connect. But it says it can make 'Emergency Calls'. Do 'Emergency Calls' use a different network?

I just called FreeUp to check if my account is OK and it is. The rep told me I need to change the APN settings and pointed me here. He told me to follow the 'Android' instructions; they're good for my 'KaiOS' phone.

Does capitalization matter in APN settings?

All right! The phone came alive.

One thing I'm still not clear on. Any idea how do you change capitalization on KaiOS? I, somehow, wrote FreeUP Mobile but I'm still not sure how! I just kept pressing buttons...

I think I found it. You press the # button. I saw it here: