Just download any IDM version for their official site and follow these steps to install it in your device.
How to Install IDM?
01. Uninstall the previous version of IDM if installed.
02. Download the installation file.
03. Run IDM 6.21 Build 5 setup file.
04. Click Next.
05. Click Next.
06. Click Next.
07. Click Next.
08. Click Finish.
09. Run IDM Then Click “Help > About IDM. You will see your IDM 6.21 Build 5 is Full Version.