Inertia Post Displays Query String

Just wondering why post request displays query string? https://prnt.sc/6rcrsqeFNHRH

Here is the method for button in my vue

mergePrepare() {
				Inertia.post(route('customers.merge.prepare',{ customers: this.mergeCustomerList }))
}

My controller

/**
     * @param MergeCustomerRequest $request
     * @return \Inertia\Response
     */
    public function mergePrepare(MergeCustomerRequest $request)
    {
        $customers = $this->customer_service->getMergeCustomer($request->customers);

        return Inertia::render('Customer/Merge', [
            'customers' => $customers,
        ]);
    }