Summarize:

In order to adjust your Sim's relationships using cheats, you'll need to use a third-party hack to enable certain in-game cheats. Sims 4 mods cannot be installed on game consoles like Xbox One or Playstation 4.  You can only install mods on the Sims 4 for PC and Mac. It's the orange link on the page.  This downloads a script file that you can add to your Sims 4 mods folder. By default, downloaded files can be found in your Downloads folder.  Locate the Tmex-AllCheats.ts4script file in your Downloads folder and right-click on it.  Click Copy and then navigate to your Sims 4 Mods folder in Windows Explorer, or Finder on Mac. The Sims 4 Mods folder is located at the following location on PC and Mac: Documents > Electronic Arts > The Sims 4 > Mods Click the icon with the Sims green diamond (plumbob) to open the Sims 4.  You can also open the Sims 4 inside Origin. After the title screen animation, the icon with three dots appears in the upper-right corner.  Click this icon to open the menu.  You can open the menu at any time during a game. It's the third option in the menu. It's the last option in the sidebar to the left of the Game Options menu. Click the checkbox next to "Enable Custom Content and Mods".  Then click the checkbox next to "Enable scripting mods". It's in the lower-right corner of the game options menu.  This saves your changes and returns to the main menu. In order for mods to take effect, you need to restart your game.  Click Exit Game then click the checkmark icon to confirm that you want to exit a game.
Go to https://www.patreon.com/posts/cheat-fix-for-22697405 in a web browser. Click Tmex-AllCheats.ts4script. Copy the script file to your Sims 4 mods folder. Start a new Sims 4 game. Click … or press Esc. Click Game Options. Click Other. Enable mods and script mods. Click Apply Changes. Click Exit Game.