Yes, it is absolutely possible to make adding a shipping method (and price) mandatory in Odoo 17 Enterprise (on-premise) — but it will require a small customization, as Odoo doesn't enforce this by default.

from odoo.exceptions import UserError

class SaleOrder(models.Model):

    _inherit = 'sale.order'

    def action_confirm(self):

        for order in self:

            if not order.carrier_id:

                raise UserError("You must select a Shipping Method before confirming the quotation.")

        return super().action_confirm()

Hope it helps