@JNGH… Metatrader 4 should run on IOS, check with your Broker for a version that is compatible to run on the IOS version you have. I’ve installed on High Sierra (10.13 ).
(See example below)
Clint started a thread which is now massive (4500+ posts) suggesting a list of Brokers and reviews from around the globe that will allow US citizens to open a “full featured” account outside of the DF issue.
Maybe start toward the bottom of the thread as this obviously will be the most up to date selection of compatible Brokers for the strategy you are proposing to run.
Hope this is of help, Cheers.