FFEDBACK STX TO ETH SEPOLIA

wow the transaction bridge is very fast now😍
but I found, there is no bridge fee using ETH sepolia.
and only use STX charge.
here I read there must be a sepolia ETH fee
Then what is my eth sepolia for, I use the sepolia faucet and my sepolia ETH is still intact, and 1 more there is no bridge confirmation to my metamask. and there is no estimated eth sepolia fee

bridge id tx : 0x489f04846b0b4320c43ee3d595055e1cffeeb1e7458fdb0a75a9a9a43023f5db

order history : 0xb4172e15a6f05a5c394c457f48c0159e5ca88f2d2357e0531ef26fab4dfde68b-0

my testnet address : ST21BCFVVA7R0BSZCZEBKQPD1QG3QGCF044053XEF
my mainet address :grin:: SP21BCFVVA7R0BSZCZEBKQPD1QG3QGCF047YQ6XQ1