'GET' instead of 'POST' with axios on deployment Heroku

Question

I pushed my project on Heroku to build my aplication, but I am getting this error.

In my localhost, everything is working fine:

This is the code for the request:

insertar()
{
  this.precioproveedor = this.precioproveedor.replace(/\./g,'')
  this.precioventa = this.precioventa.replace(/\./g,'')
  axios
  .post('../procesarProductos/1/',
  { idafiliado: this.idafiliado,
    id: this.id, 
    cantidad: this.cantidad,
    nombre: this.nombre,
    precioventa: this.precioventa,
    precioproveedor: this.precioproveedor,
    imgurl: this.imgurl})
  .then(response => {this.productos = response.data;swal("El producto ha sido agregado", "", "success")})
  .catch(e => (swal("Ha surgido un problema", "Por favor comunicarte a través de un reporte", "error")))
  this.limpiar()
},

Before getting this error, I got another error, that was 'Mixed content' and I fixed that with a meta tag.