Hi, you can use the plugin command "Gain Reputation" to gain reputation, "Lose Reputation" to lose reputation, or "Set Reputation" to set a reputation to a static amount (might gain or lose depending on the player's current rep).
Viewing post in [CGMZ] Reputations for RPG Maker MZ comments
When you want the player to gain 100 rep (for example) in your event, click to add a new event command -> select page 3 and under advanced select plugin command -> select the reputations plugin, select Gain Reputation command, and type in the reputation id you want to gain and 100 for the amount. Then, when the player reaches that event command, they will gain 100 reputation.
If you want the player to gain more or less than 100 reputation, type in a different number that is greater or less than 100 in your plugin command.
For example like this: