How to set speed limit for my connected devices

I have 7 devices connected i want to just give one of my devices 10mbps limit and keep all devices as it is how can i go it
In tp link i can do it.

With the tp link firmware you will not be able to set a speed limit, you would have to install openwrt or a router that has that function.

no you made a mistake i just added that as a reference

The same question was raised just a few days ago. Please see if you can find useful information here:

Install the luci-i18n-nft-qos package which allows you to control the speed of the connected devices, it should be noted that you have to assign each one a static IP.