There are 3 reasons that may cause this issue.
To be able to see the screenshots of your employees' computers when they are working, please make sure they have installed the LogWork software. This feature is available only if the software is installed.
It is possible to download the software in the "Download" section. Then, it is possible to select the software for Windows or Mac.
After installing, please login into your account in software and try to start the timer.
You can also restart the LogWork desktop software or restart your PC after installing it.
Your screenshot frequency can be set in the "Workspace settings". Make sure this option is not disabled. Or, you can set it in the "Team" section if you have chosen per user settings option.
Please, keep in mind that you must wait for a few minutes for the first screenshot to be taken. For example, in the Free Plan, the first screenshot is taken after 20 minutes of work. You will see them in the "Timeline" section.