I don’t have mine yet so can’t confirm for you, but an alternative I think is decent is Roamless. Rather than buying data for a set amount of time, you add funds to your account and it takes from those funds as you use data at a rate of $3.25/GB in the US.
So for $10, you would get a little over 3GB rather than 5GB with T-Mobile, but it wouldn’t expire in 5 months. I think that’s better if you are a really light user. It also uses AT&T in the US and works in 60+ other countries at different rates.
They have a referral program also. You get $3 in credit when you sign up with someone’s referral code and they get $3 also. You also get a $5 credit the first time you add $20 to your account, so you can get $28 worth of data for $20 if you do that which would give you 8.6GB of data that again doesn’t expire. I don’t want to post a shameless referral code so if you’re interested, you can send me a DM and I’ll send you my code.