I haven’t used myself, but others on this sub have claimed this one works good enough.
That modem is fine. You can connect the SMA 4g to this.
Two antennas inside this. has 10ft of cable. works great.
I was able to use a set from Amazon
Goupchn U.FL/IPEX/IPX to SMA... https://www.amazon.com/dp/B095WZPCW3?ref=ppx_pop_mob_ap_share
11dBi High Gain 3G 4G/LTE... https://www.amazon.com/dp/B08CRN6HYY?ref=ppx_pop_mob_ap_share