Ability to change password used to restrict access to Outlook pst files appears to have disappeared.

Change password to gain access to Outlook. 

I wish to change the password I currently have to get into Outlook used in Office 365 when it loads on PC which in the past has been set / reset by opening the application on PC and doing the following  : – 

Select  - File  -  account settings -  account settings - Select the profile , - select tab data files, select the appropriate data pst. file, choose settings and select change password. 

This is still shown as the method to change password for access to a pst file on the Microsoft support pages.

When these options are selected now the only option that now presents is the ability to compact the file. 

The password re-set option has disappeared. Hence I cannot change the password I use to gain access to outlook.

I run Microsoft 365 Apps for business and Windows 10 pro.

I should be grateful if someone could please advise how to now achieve having a changeable password for access to the Outlook App alone - now this facility appears to have disappeared.

Thanks