This is from a prior post by TriBar and explains the License situation.
Hi, and welcome to the Forum.
You can install Litchi on as many devices as you want as long as you are using the same main Google, Apple or Amazon account. Please note that this is only valid if the devices are on the same platform (Google, Amazon or iOS). Google, Amazon and iOS use different licensing systems, if you wish to use Litchi on two or more platforms you will need to purchase it on each one.