Disable sleep mode on Mac
1. Use the Apple Menu to launch the System Settings app on your Mac.
2. Scroll down to find Displays in the left sidebar and click to open it.
3. Scroll down the right sidebar and open the Advanced… setting.
4. Under Battery & Energy, enable the toggle next to Prevent automatic sleeping on power adapter when the display is off.
5. Use the Done button to save changes.
Now even when the display is off, your Mac will not sleep. However, note that this setting only works when our Mac is connected to a power source. If your Mac is on battery power, it will sleep after the display turns off.
1) Open System Preferences: Click the System Preferences icon 
in the Dock, or choose Apple menu 
> System Preferences. (more details https://support.apple.com/guide/macbook-air/system-preferences-apda966cb8af/2020/mac/10.15.3)
2) Open Battery
3) Open Power Adapter options, and set the options as on the image:
1) Open System Preferences: Click the System Preferences icon in the Dock, or choose Apple menu > System Preferences. (more details https://support.apple.com/guide/macbook-air/system-preferences-apda966cb8af/2020/mac/10.15.3)
2) Open Energy Saver
3) Open Power Adapter options, and set the options as on the image:
Feel free to contact me if you have any questions [email protected]