It's me again with the old non-smart phone, the Pantech Matrix C740. I have phone service and SMS working fine, but haven't been successful with internet or MMS. Maybe this will be irrelevant soon if I stay on the free plan and we lose the data allotment (I still have it for now). But I'm curious to get it working if I can.
Anyway, the settings are a bit different than what I'm familiar with on Android. The browser is an older protocol called WAP: Wireless Application Protocol - Wikipedia
There's a WAP Profile with fields Profile Name, Home URL, Connection Type (which I set to the Profile/APN I set up for FreeUP), Proxy Address, and Proxy Port. As far as I can see, FreeUP doesn't publish some of these. Here's an example of a different MVNO who does: H2O Wireless: Prepaid Unlimited Plans with No Contract
I've taken some guesses but no luck, all addresses I try to access in the browser give me "the requested host was not found".
Not sure if MMS is failing due to the browser being configured incorrectly or some other problem. For MMS there's an MMS Profile with Profile Name, MMSC, Connection Type, Proxy Address, and Proxy Port. I guess I haven't deduced correctly on how to fill these out (I referred to the Android settings and did my best.)
I did put in a ticket with FreeUP about a week ago and haven't heard back.
Anyone have any ideas/suggestions? In any case I found it interesting to read about the WAP Protocol. 
@RingieDingie-----I saw these WIFI Dongle APN settings for FreeUP on the below site. Scroll down to the bottom of the page. I doubt they will be of help, and that's all I know.
I was also going to suggest that you could ask your APN questions on FreeUP's Twitter feed with more luck getting a quick response. But, when going through FreeUp's Tweets and replies, I was surprised to see that from July 2017 up to the present the twitter site has been a virtual ghost town with only 2 tweets by someone other than FreeUP, one of which asked about the coupons rewards not crediting, and so maybe you can go liven up FreeUp's twitterverse, and, since you would be the only one there, you might get a quick response.
"@freeupmobile The print coupons reward is not working. You are supposed to get .24 cents a day for printing at least 1 coupon per day. I have printed one a day for the last six days in a row but have not received any points for it."
12:54 PM - 6 May 2018
I've been reading about WAP off-and-on today. I haven't made any progress on settings to suggest......
WAP came out in 1999...
Thanks much, will review that and see if I have any luck!
Yup, it's an older phone - not quite that old though. I found a review of it from 2008, think that's when it came out.