Reference: https://github.com/paulmillr/noble-secp256k1/blob/976d3b59bbd30f2d28638e5420b219fd3d829169/index.ts#L669-L682 Using this function from noble-secp256k1 as its not exported by library till v1.5.5 Concatenates several Uint8Arrays into one

Calculate the base64 encoded string length for a given input length. This is equivalent to the byte length when the string is ASCII or UTF8-8 encoded.

Converts hex input string to bigint

Reference: https://github.com/paulmillr/noble-secp256k1/blob/976d3b59bbd30f2d28638e5420b219fd3d829169/index.ts#L726-L740 Using this function from noble-secp256k1 as its not exported by library till v1.5.5 Converts hex string to Uint8Array