Funding is the one thing you can not do within Options Cafe. You must login to your Tradier Brokerage account and fund through Tradier. Here is the direct link to fund your account.
As a reminder, commission-free trading with Options Cafe is powered by Tradier brokerage. All trades through Options Cafe are routed through Tradier. In fact, you can login to Tradier directly and use their web interface to trade as well.