Is online trading in gold, currencies, and oil permissible or forbidden, knowing that there is no financial leverage, but rather an increase in the value of the amount traded, and 3% of the profit is deducted, and the profit is deposited into the wallet when the deal is closed, and withdrawals are made within two or three days?

It is not permissible to trade in the international market for gold, silver, currencies, and other commodities through a brokerage firm that raises the value of what one trades with (financial leverage), because the reality of this increase is a loan that brings benefit, and every loan that brings benefit is usury (riba). If one avoids this and other prohibitions, then there is no harm in trading in the international market, while observing the Shariah conditions for trading in gold, silver, and currencies.