Custom Activity - Class : Could not load file or assembly

We have created a custom Activity which uses Death By Captcha client, the code is running fine independently, but when converted to custom activity below error is encountered.
Kindly Help

Class 1: Could not load file or assembly ‘DeathByCaptcha, Version=1.0.6278.28767, Culture=neutral, PublicKeyToken=null’ or one of its dependencies. The system cannot find the file specified.

whatever the assembly you have imported while creating the dll or building the code for it, try to import the same in the uipath studio as well. Then check if it is working