but I don't see redeem script for any of the addresses, can you tell me how to generate redeem script based on private key
because if I want to use coinb.in to create tx, I need redeem script to retrieve the segwit address' utxo
can you point me in the right direction on this matter
You will see that the bitcoin core will return an address that starts with 3xxxxxxx which is the same one that is listed in iancoleman.io/bip39/ that starts with 3xxxx
Note that you must have the core bitcoin synchronized to add a legacy address to the segwit, both legacy and segwti addresses share the same private key...