Service error in ASP.NET Core

I am implementing a service in ASP.NET Core but it gives me a procedure error, as I understand it is because of the type of variable that I am entering and I sent a string instead of int , I changed it but I still get the same error, what else should I do implement or change so that it works for me and stops that error. Also, as I would return several returns in my postman, I mean that it executes several queries in a single service, one by one. Thanks for your help beforehand.

this is my controller

using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Data.SqlClient;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.IdentityModel.Tokens;
using Salesws.Context;
using Salesws.Models;
using Salesws.Service;
using Salesws.Service.Interfaces;
using System;
using System.Collections.Generic;
using System.Data;
using System.IdentityModel.Tokens.Jwt;
using System.Linq;
using System.Security.Claims;
using System.Text;
using System.Threading.Tasks;

// For more information on enabling Web API for empty projects, visit https://go.microsoft.com/fwlink/?LinkID=397860

namespace Salesws.RestControllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class LoginController : ControllerBase
    {

        private IConfiguration _config;
        //Contexto de la base de datos SVM
        private readonly SVMcontext _context;
        private readonly IFechaService _fechaService;
        private readonly ILambSelLiquidacionService _iamb_Sel_Liquidacion;
        public LoginController(IConfiguration config, SVMcontext context,IFechaService fechaService,ILambSelLiquidacionService amb_Sel_LiquidacionService)
        {
            _config = config;
            _context = context;
            _fechaService = fechaService;
            _iamb_Sel_Liquidacion = amb_Sel_LiquidacionService;
        }

        [HttpGet("liqui/{celular}/{cod_liquidacion}")]
        public ActionResult liqui()
        {
            var liqui = _iamb_Sel_Liquidacion.liquidacion();
            return Ok(liqui);
        }
    }
}

this is my repository

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Salesws.Service.Interfaces
{
    public interface ILambSelLiquidacionRepository
    {
        int liquidacion();
    }
}

this my service

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Salesws.Service.Interfaces
{
    public interface ILambSelLiquidacionService
    {
        int liquidacion();
    }
}

I implement my service

using Salesws.Service.Interfaces;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Salesws.Service
{
    public class AmbSelLiquidacionService:ILambSelLiquidacionService
    {
        private ILambSelLiquidacionRepository _liqui;
        public AmbSelLiquidacionService(ILambSelLiquidacionRepository liqui)
        {
            _liqui = liqui;
        }


        int ILambSelLiquidacionService.liquidacion()
        {
            return _liqui.liquidacion();
        }
    }
}

implement the procedure

using Microsoft.EntityFrameworkCore;
using Salesws.Context;
using Salesws.Service.Interfaces;
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;
using System.Linq;
using System.Threading.Tasks;

namespace Salesws.Models
{
    public class AmbSelLiquidacionRepository:ILambSelLiquidacionRepository
    {
        private readonly SVMcontext _context;


        public AmbSelLiquidacionRepository(SVMcontext context)
        {
            _context = context;
        }

        public int liquidacion()
        {
            int liqui = 0;
            using (DbCommand command = _context.Database.GetDbConnection().CreateCommand())
            {
                command.CommandText = "dbo.amb_sel_liquidacion";
                command.CommandType = CommandType.StoredProcedure;
                _context.Database.OpenConnection();
                using (var resultado = command.ExecuteReader())
                {
                    while (resultado.Read())
                    {
                        liqui = (int)resultado[0];
                    }
                }
                _context.Database.CloseConnection();
            }
            return liqui;
        }
    }
}

This is the error