Before using Blitz, or "self-custodial" wallet of satoshi, or any Breez wallet, please education yourself on this person: https://en.wikipedia.org/wiki/David_A._Marcus
This person has full control of your balances, sees all your internet traffic, everything -- the "self-custodial" thing is very misleading marketing and isn't really intended for end users, it's more so these companies can go to government/regulators and say "look, we don't custody funds!"
In reality anything using Spark's API like these wallets is super-dangerous.....