Thx pooya87, I did exactly what you said but with this lib extension (toZprv) for Nbitcoin :
https://github.com/zkSNACKs/WalletWasabi/blob/abebff2b0703b0758ac8b97ba4b4f1cbd3a605eb/WalletWasabi/Extensions/NBitcoinExtensions.cs
An it works, can import my master key with BIP84 derivation path.
Thx a lot !!
PS : Now I need to understand why I cannot generate the good ScriptPubKey from my Extended Master Key, to query electrs (electrum rust server) server.
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