Step1: Get 0.5 ETH from this Sepolia ETH Faucet

Step 2: Open your wallet in browser extension

Step 3: Select your wallet network as Ethereum Sepolia

Step 4: Send Sepolia ETH to Blast Bridge 0xc644cc19d2A9388b71dd1dEde07cFFC73237Dca8 (refer to Blast docs here)

Step 5: Select your wallet network back to Blast Sepolia