LilyGO is known manufacturer of development boards, kits and modules TTGO, which contains diverse variantions of electronic components and functionality.
Today they released a new board called TTGO T-Call contains WiFi and Bluetooth module ESP32 together with GPRS module SIM800L. The device can be powered by USB-C connector or battery.
You can buy it on aliexpress website, but at this moment, there is not so much info. More infor you can find on github of project and of course on website of manufacturer LilyGO.
The github shows you the connection between ESP32 and SIM800L and also example code for this board.
More info you can find on website of manufacturer. You meet with specification, pinout or mechanical drawing.
USB-UART is used typical CP2104, power supply voltage is from 2.7V to 3.6V, the current in deep-sleep mode is only 300 uA and only Nano SIM is supported.
There is USB-C connector and also battery connector on the board.
The price for TTGO T-Call is 14.63 USD + 5.35 USD shipping (in my case - Czech Republic).