go to the site or app, sign-in or register if you don't have an account so they can reach you, then browse the item you want to source, one you find the item you want contact the seller, you can message them right from the app, then you can have more information on the item and if they will be able to modify it to your liking. if you have to make modification they will send you samples of your modification, usually this is the tidy part because they might not get it right the first time and you have to correct them several times, it is best if you can find Chinese speaker it will make the communication more productive since they are a little short in English . then for the payment you can use a credit card or find people that can send you the the money to china, or you could ask for LC from bank and for the logistics the sellers will usually provide you with the fastest and cheapest ways or you can choose yourself, there are also local expresses that work between china and Ethiopia