my own preference is Oanda, but that doesn’t matter
what matters is to choose a broker regulated by the FCA, CFTC, NFA or ASIC, as advised above, and make sure your account is regulated by that regulator - it has to be a PROPERLY regulated brokerage, otherwise you think you have some potential protection when you actually have none
that means regulated by the FCA, by ASIC, or by the CFTC or NFA
other regulators in obscure Caribbean, Pacific and other small countries are fake/pretend ones (ok, CySEC in Cyprus isn’t completely horrible, but it’s the only other semi-respectable one) and they’re paid for by the people they “regulate” and they never rule against their paymasters