How to Open New Tabs, Search, and Bookmarks When Clicking Links in Firefox
Open Firefox Firefox browser settings
After entering about:config in the address bar of Firefox and pressing the Enter key, a warning page opens, click "Accept the risk and continue", as shown in the figure below
Open a link on a webpage in a new tab (click a link to open a new tab)
Enter browser.urlbar.openintab in the window and double-click the displayed value to change it to true
Open search results in a new tab
Enter browser.search.openintab in the window and double-click the displayed value to change it to true
Open bookmark in new tab
Enter browser.tabs.loadBookmarksInTabs in the window and double-click the displayed value to change it to true
Double click the displayed value to change to true