Japanese beetles are an invasive species that are very difficult to get rid of.  Their life cycle begins as an egg deposited in the soil and develops into the white grubs that can severely damage turf if they are in sufficient numbers.  Once they reach the adult stage, they feed on many plants they are attracted to.  Using insecticides on the adult beetles is not recommended since the chemicals can adversely affect beneficial insects and wildlife.  The most effective control is to reduce the grub population.  Separately, some plants are more attractive to the beetles than others, based on aromas.  The links below discuss Integrated Pest Management for Japanese beetles, life cycle of the beetles, and additional management strategies.   Japanese beetles are a major problem in my garden - particularly on roses and hibiscus.  I used to spray insecticides to treat them until I learned that I was affecting pollinators and other beneficial insects.  For now, I don't try to physically remove them unless I happen to be working on the affected plant.  Dropping them into soapy water or crushing them works well.  At this point, I haven't gone after the grubs, but may decide to try the Milky Spores suggested in a couple of the articles below.  Good luck to you with Japanese beetles.
https://www.aphis.usda.gov/sites/default/files/JBhandbook.pdf
https://extension.umn.edu/yard-and-garden-insects/japanese-beetles#curative-insecticides-1592863
https://northerngardener.org/japanese-beetle-solutions/