Yes, you can login to Spekit via Salesforce even if you use Single Sign-On (SSO) providers such as Okta.
There is one caveat: You must be logged into Salesforce via your SSO provider BEFORE you attempt to login to Spekit
Once you are logged into Salesforce via SSO (as you normally do):
Go to Spekit login
Click on "Login with Salesforce production" (or sandbox if your account is a sandbox account)
You'll see your username and password pre-saved on the next screen
Click on your Salesforce username and you'll be logged into Spekit via Salesforce
The only thing to remember is to be logged into Salesforce via SSO before you attempt the steps above