Were you inputting your Public Posting Key or your Private Posting Key?

To get the Private Posting Key you need to go to

https://wallet.hive.blog/@smithlabs/transfers (if you don't want to click on my link, you click on your icon -> Wallet to get to this screen)

Then log in -> click on Keys and Permissions.

It should now show your Private Posting Key. You can log in with that onto anywhere, hive.blog, peakd, palnet, leofinance.io, etc.