How do I change the Ctrl+F shortcut to open Slack's search function?

Click on your profile picture in the top-right corner, then click on “Preferences”.

Go to the Slack tab in Wavebox.
Click on your profile picture in the top-right corner, then click on 'Preferences'.
Next, click on the 'Advanced' option.
Look for the 'Search options' section, and then tick the checkbox labelled 'Ctrl + F starts a Slack search'.