No seed phrase backup. Rizful is design for normies to keep small amounts of sats in. There is a lot of disagreement on this issue, but our belief is that normies absolutely can't be trusted with seed phrases, and if you give them one, they will either lose it or someone will scam them into giving it up in a chat.
Discussion
To clarify. At most, normies can be trusted with one (1) seed phrase, which they should use with their hardware wallet. (If they're competent enough.) This is where they should keep 99.9% of their sats. The remaining 0.01% of their sats should be put in a secure but very-easy-to-use web-based system like Rizful.com.