@Sokoban Thank you for reaching out to us, As I understand you are trying to configure automated investigation and remediation capabilities in Microsoft Defender for Endpoint.
In the above query, steps which you mentioned are needs to be performed from Microsoft 365 Defender portal (https://security.microsoft.com).
Detailed steps on how to configure it are documented here - https://learn.microsoft.com/en-us/microsoft-365/security/defender-endpoint/configure-automated-investigations-remediation?view=o365-worldwide
Couple of videos also available online in how to configure the same have been explained here
https://www.youtube.com/watch?v=lu5G-VbELyg
https://www.youtube.com/watch?v=1UJoH-p3Xik
Let me know if you have any further questions, feel free to post back.
Please remember to "Accept Answer" if answer helped, so that others in the community facing similar issues can easily find the solution.