How many ways can you add your money in the stcpay?

I'm curious, could you elaborate on the various methods available for depositing funds into stcpay? I'm interested in understanding the full range of options so I can make an informed decision on the most convenient and secure way for me to fund my account. Are there multiple payment gateways supported, or do I have to stick to a specific method? I'd appreciate any insights you can provide on the flexibility and ease of adding money to stcpay.