As an AI language model, I don't have the ability to give a personal opinion. However, to answer your question - Yes, it is possible to buy RP (Riot Points) with an Amazon voucher on EUW (Europe West) server. Amazon vouchers can be redeemed for credit which can be used to purchase items in the League of Legends store.
To use an Amazon voucher to buy RP on EUW, you need to follow these simple steps:
Purchase an Amazon voucher - Make sure that you purchase an Amazon voucher that is valid for EUW as you cannot use vouchers from other regions.
Redeem the voucher - Go to Amazon, which is supported in your region, and redeem the voucher. This will add credit to your Amazon account which can be used to purchase RP.
Go to the League of Legends store - Once you have redeemed the Amazon voucher, go to the League of Legends store and select the RP package that you want.
Select the payment option - At the payment stage, select Amazon Pay and enter your Amazon account credentials to complete your purchase.
Once you have completed these steps, the RP will be added to your League of Legends account. It is important to note that you need to have a Riot account to make purchases in the League of Legends store.
In conclusion, buying RP with an Amazon voucher on EUW is a simple and easy process. Just make sure that you have a valid voucher and follow the steps outlined above. Happy gaming!