Before proceeding with your Bitrix24 migration setup, previously you should install Bitrix24 application. To get started with your data transfer, just follow a few steps below:
1. Go to Bitrix24 App web page and press "Install" button:
2. Then, provide your Bitrix24 URL in the coresponding field:
3. And click "Install" to add the application to your Bitrix24 account.
After that, you may simply proceed with Data2CRM migration wizard - http://app.data2crm.com/ and complete migration steps.