Well, the TFL0124 KIT I bought (https://wiki.dfrobot.com/SIM7600CE-T_4G(LTE)_Shield_V1.0_SKU_TEL0124) was delivered with a small PCB antenna with a fixed 10cm cable that connects directly to an U.FL connector on the board. There are definitely no SMA connectors on the board itself and there were no SMA adapter cable delivered either.

However, external antennas typically comes with the more robust SMA connectors why a short adapter cable from U.FL to SMA is needed.

Thanks a lot for the replies. I could not find any clear information in the documentation so to be on the safe side I ordered adapter cables with MMCX as well as U.FL and I can confirm the connector on the board is U.FL.