These are five super simple tips that you can use when you are looking for ideas to get kids to write
1. ask them to draw one thing they saw during the day,
2. have them describe what they saw in words
3. write them part of a very simple story and let them finish it in their own words
4. tell them a story, and then ask them to write it down after you are done
5. give them a reward for every writing piece they complete
Kids need inspiration. Above all, they need to know that someone out there loves when they take the initiative to describe themselves and their world in written form. Be that person, and challenge them to see different perspectives. Care less about the actual meaning and the grammar part because they have plenty of time to correct it.