During a recent Special Interest Group (SIG) meeting, one of our members asked if anyone had experience getting relatives to take a DNA test to help with the family genealogy. He was having difficulty with two older uncles volunteering to take a test. This is not unusual, for people of all ages to question the need.
After doing a quick Google search, I found this simple article with a few great tips. If you have this challenge with relatives, check this out for some good ideas: https://www.familyhistoryfanatics.com/post/convince-relative-to-dna-test