Commands Daily! The generators I use are listed here:

Here:

https://minecraftcommand.science/ 

Bit more customizable generator:

http://mapmaking.fr/give1.14/

More complicated sign+book generator:

https://minecraftjson.com/

Entity summoner

https://mcstacker.bimbimma.com/

More generators just if you use multiple generators and upload them here like me:

https://www.digminecraft.com/generators/index.php