Project Creation, Enable API Access in Google Cloud Console
& Add Scopes at Domain Level

Go to the cloud platform https://console.developers.google.com/ and Sign in

After successful sign in, home screen comes up. Go to IAM & Admin >> Create a Project to initiate project creation.

Then Enter the project name and click on Create button to generate new project.

After successful creation, click on API & Services > Credentials as given below:

Choose Credentials from the navigation menu and click on Credentials tab. Then select Create Credentials.

Now click on Create Credentials > Service Account as shown below:

Now, in Service account details section, enter Service Account Name & Click on CREATE AND CONTINUE button.

Now, grant service account permissions (optional) for that click on the Select a role option. Choose Project >> Owner from drop down. After that click on Continue and then Done button.

Next, click on Edit button under the Actions.

Service account details screen would be displayed, then click on Keys tab in same page. After that click on Add key >> Create new key and Select an option P12 from key type and click on Create button:

Download the P12 file and save securely in your local system. This is the p12 file which you need to browse within SysTools Google Vault Downloader.

Now, go to the Details tab under the Service Accounts window. Here, you will see the Client / Unique ID. Copy this ID as you will need this ID afterwards.

Now go to Menu > APIs and Services > Library. Now open and Enable each library as given below:

1. Admin SDK API
2. G Suite Vault API

Open and Enable each library as given below:

Enable Admin SDK API

Enable G Suite Vault API

Then Go to Admin Console and you will be redirected to the browser where you have to login using the source/destination admin email id .

After successful login, select the Security option.

Navigate to API Controls option and click on it.

From Domain-Wide Delegation section, select "MANAGE DOMAIN-WIDE DELEGATION".

Under the Domain-Wide Delegation screen, click on "Add New".

Manage API client Access screen comes up, enter earlier created Unique Id (Prefer Step 10 in “Client Name” field and below given permissions in “One or More API Scopes” fields as shown below:

https://www.googleapis.com/auth/ediscovery,
https://www.googleapis.com/auth/devstorage.full_control,
https://www.googleapis.com/auth/admin.directory.user.readonly,
https://www.googleapis.com/auth/admin.directory.userschema.readonly,
https://www.googleapis.com/auth/admin.directory.rolemanagement.readonly

After successful authorization, above entered details will be added and shown in list as given below