Please see the Tutorial and read about "Panelize". If you choose to panelise by hand, put the V-Cut lines on the Board Outline layer and not the Mechanical layer: [https://easyeda.com/forum/topic/V-Cut-lines-must-be-drawn-on-the-Board-Outline-Layer-cbe1471cf93d410ea3141e431d52bb8b](https://easyeda.com/forum/topic/V-Cut-lines-must-be-drawn-on-the-Board-Outline-Layer-cbe1471cf93d410ea3141e431d52bb8b)

[https://docs.easyeda.com/en/PCB/Panelize/index.html](https://docs.easyeda.com/en/PCB/Panelize/index.html)

@andyfierman thank you, english is not my native language, did not find it right away