If you already have a Traderwave account. you can change your plan via the “Subscription Plans” setting after you logged in to the Traderwave app.
If you have not entered you payment method before, you will first be brought to a page for you to enter them.
After you add your payment method, click on the try button and you will be brought back to the subscription page.
You can then click on the desired paid plan you want to switch to as shown below.