Generate AES-GCM 256 bit Encryption key using Azure Key Vault Managed HSM

Question

I'm trying to generate an AES-GCM algorithm based encryption to be used in my utility for encrypting and decrypting data.

Now, based on the Azure documentation I understand that AES-GCM key can be obtained via selecting AES-HSM key type, select then 128 or 256 bit key size, select key operations = Encrypt, Decrypt and unselect the rest of checkboxes.

Questions:

How do I use this key into my utility as a static key just for testing purposes? I'm not able to find enough documentation on how to perform this operation.

I'd download the backup copy of this key, but its a long string and my utility needs max 24 length string, which then converts it into byte[]

Would appreciate any inputs or guidance on how can I consume this generated key.