Domestic formal can go to the bank for foreign exchange transactions, but there are many restrictions. The operability is poor and you can't trade with leverage. But the integrity is very good.
Irregular is the agency of various foreign financial institutions, and the accounts are all opened abroad, so it is difficult to ensure the safety of your funds. This kind of domestic agency is illegal.
The advantage is that the lever can be up to 400 times, and the operability is strong. The vast majority of domestic foreign exchange speculation is in this form.