Trying to boost Wireless Broadband signal

Further to a recent post and having no other option but Satellite Broadband which is capped. It seems Vodafone gives the best coverage here for wireless Broadband with a router. I tried Three and Eir Sims and they were really poor. I use Vodafone for my mobile. I don't suppose I would get away with just hotspotting. Or does the router also improve the signal?

Vodafone works... Kind of. So a boost would be great. Is the below worth buying. The Poynting-XPOL 2 5G Antenna. Or is there a cheaper option? Or is it worth buying at all?

If so how do you find out where the mast is. Or is it a case of trial and error?

https://www.amazon.co.uk/Poynting-XPOL-2-5G-Antenna/dp/B081QCWTZX/ref=mp_s_a_1_5?keywords=Poynting&qid=1670012578&sr=8-5