So you want to see on your laptop what the robot's camera sees.
I'd start with this
https://sixfab.com/product/raspberry-pi-3g-4glte-base-shield-v2/?attribute_header-type=with+long+header&utm_medium=ppc&utm_campaign=US+Smart+Shopping&utm_term=&utm_source=adwords&hsa_src=u&hsa_net=adwords&hsa_kw=&hsa_tgt=pla-293946777986&hsa_ad=355845382964&hsa_grp=78850140224&hsa_mt=&hsa_acc=6308888758&hsa_ver=3&hsa_cam=2037647658&gclid=EAIaIQobChMIjpf_mN-x6AIVTNyGCh33jgdYEAYYASABEgIWrPD_BwE
then experiment to see what picture size and frame rate the 4G will support.
(forum adds extra characters to start and end, just delete them)