Where do I get the credentials from?

I just shared an ext HDD attached to my main pc in Windows 10.
Then from my laptop I went to Macrium Reflect to use that shared ext HDD. But when I had chosen it, Reflect is asking me for a user name and password.
Is that the credentials I use to login to the main pc, or was I supposed to create the credentials specifically for this laptop's network use?
Thank you guys!

Bree said:

You need to provide the name and password of an account on the PC you are trying to connect to. Once you have given this your permissions on that share will be those of the account you used.

Thanks for that Bree. Are you saying that the credentials I need to enter in Reflect in my laptop are those I use to login to my main pc? Being my Hotmail credentials?

I see. That was a great reply, very clear, I appreciate it very much 👍

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Bree said:

Yes. to access the share on your main pc you need to provide the name/password of an account that exists on that pc. If you have more than one account on your main pc you could use any of them.
To connect using your Microsoft account login on that pc the credentials you need would be the email address as the name, and the password for your MS account (NOT a PIN).
If you have problems connecting, it may make life simpler if you create a new local account and password, just for use by other PCs wehen connecting to the shares.

Unfortunately using my MS credentials did not work. I guess I'll create a local account without a MS account.

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I created a new Local account (without an MS account), but still not working. It says "Access denied".
What else can I try?

Bree said:

Turn off Password Protected sharing.
Turn On or Off Password Protected Sharing in Windows 10There are two permissions you can check on the main machine where you created the share and the local account.
The first is the Share permission, set this to: Everyone - full control.
The second is the NTFS file permissions on the Security tab of the folder being shared, the local account you created need access permission. The simplest way to make sure is that you give Everyone Full control here too.

That sounds very promising! Thank you so much Bree, I'll give it asap :)

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Bree said:

Turn off Password Protected sharing.Turn On or Off Password Protected Sharing in Windows 10There are two permissions you can check on the main machine where you created the share and the local account.The first is the Share permission, set this to: Everyone - full control.The second is the NTFS file permissions on the Security tab of the folder being shared, the local account you created need access permission. The simplest way to make sure is that you give Everyone Full control here too.

That certainly did it! Thank you so much Bree :)