To override the user agent string from Chrome DevTools:
Open Chrome DevTools, either by right-click and select Inspect. Or, using shortcut keys press Command+Option+C (Mac) or Control+Shift+C (Windows, Linux, Chrome OS).
Press Command+Shift+P (Mac) or Control+Shift+P (Windows, Linux, Chrome OS) to open the Command Menu.
Figure 1. The Command Menu
network conditions, select Show Network conditions, and press Enter to open the Network conditions tab.
In the User agent section disable the Select automatically checkbox.
Select "Googlebot" for the user agent string from the list.
Reload the current page.
Tools for Frequent Switchers
If you find yourself switching User Agent often, you may want to install a plugin that gives you quicker access. A plugin like User-Agent Switcher for Chrome makes it easier to change agent at the click of a button:
However, you do have to do a little extra initial legwork to set it up with the specifics of the agents you want to spoof. So this tool is only worthwhile if you think you'll be switching agent more than once.
If you do go down this route, please check out the list of google bot User Agents for details you can copy and paste into your User-Agent Switcher plugin configuration.