odoo16/addons/website_livechat/security/website_livechat.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo noupdate="1">

        <record id="im_livechat_channel_rule_public" model="ir.rule">
            <field name="name">website_livechat.channel.public</field>
            <field name="model_id" ref="im_livechat.model_im_livechat_channel"/>
            <field name="domain_force">[('website_published', '=', True)]</field>
            <field name="groups" eval="[(4, ref('base.group_public')), (4, ref('base.group_portal'))]"/>
            <field name="perm_read" eval="1"/>
            <field name="perm_create" eval="0"/>
            <field name="perm_write" eval="0"/>
            <field name="perm_unlink" eval="0"/>
        </record>

</odoo>