How Do You Pay TXTag Tolls If You Are From Out Of State?

I visited Texas early last month, and when I went online, I couldn't pay my toll.

Fun fact: My Massachusetts licence plate is an EV licence plate so it is something more like EV or VE then followed by 4 different characters.

TxTag didn't work that well, but I have used a myriad of toll roads throughout my times in Houston and Dallas.