You need a continuity tester, they are about $20 on Amazon.
https://www.amazon.com/Grounding-Continuity-Universal-Included-Effectiveness/dp/B096WG32VB/ref=asc_df_B096WG32VB/?tag=hyprod-20&linkCode=df0&hvadid=533377585108&hvpos=&hvnetw=g&hvrand=12828125957535825858&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=1014895&hvtargid=pla-1415051867018&psc=1