odoo16/addons/purchase_requisition/data/purchase_requisition_data.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <data noupdate="1">
        <record id="type_single" model="purchase.requisition.type">
            <field name="name">Blanket Order</field>
            <field name="sequence">3</field>
            <field name="quantity_copy">none</field>
        </record>
        <record id="seq_blanket_order" model="ir.sequence">
            <field name="name">Blanket Order</field>
            <field name="code">purchase.requisition.blanket.order</field>
            <field name="prefix">BO</field>
            <field name="padding">5</field>
            <field name="company_id" eval="False"></field>
        </record>
    </data>
</odoo>