Rachel S. answered 08/01/19
Patient and Organized Tutor Specializing in Test Prep
The teacher above beautifully explained some things you can do, and to which, I would add: start small, and build up.
First, start at a time when your child is generally attentive but not full of energy. Bedtime is a popular time because you can ensure screen-free attention and the child is "winding down" for bed. But, that might not work for everyone. If right-after-dinner works for you, that's fine too. Just try to pick the same time every day so the habit begins to reinforce itself.
Start small; 5-10 minutes. Keeping it short keeps it fun and light; avoiding frustration, and leaves your child wanting more. THAT is good!
After a few weeks, or whenever the kiddo seems ready to do more, you can slowly expand the time by 5-10 minute blocks. Maybe add a few more questions, or read a longer or more complex passage. And remember, this isn't a hard rule; some days will be better than others. Read your child's moods; encourage him/her to focus, but try not push too hard into a state of frustration.
Good luck, and enjoy!