1. Create a Chat Agent Configuration.
2. Enable “Visitor Blocking Enabled”.
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3. Add Agents or their profiles to it.
4. Now agents can view Block icon.
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Block Unwanted Chat customers:
https://help.salesforce.com/articleView?id=sf.live_agent_block_IPs_enduser.htm&type=5
Create an IP Blocking Rule to Block Chat Visitors
https://help.salesforce.com/articleView?id=sf.live_agent_block_IPs_admin_create_blocking_rule.htm&type=5
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