Use same string expressions as in miniscript. For example: "sha256(cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204)" or "ripemd160(095ff41131e5946f3c85f79e44adbcf8e27e080e)"
Accepted functions: sha256, hash256, ripemd160, hash160
Digests must be: 64-character HEX for sha256, hash160 or 30-character HEX for ripemd160 or hash160.
Hex encoded preimage. Preimages are always 32 bytes (so, 64 character in hex).
Preimage
Descriptor
Preimage