"Bug" Foreign keys do not exist is just an int field, causing errors

I have a table
company and other group and product table
the product table has a foreign key (FK) which is the company ID, when I add information through:

await strapi.services.product.create({
      'name': data.name,
      'company': ids.idCompany, //FK
      'price': data.price,
      'on_off': data.onOff,
      'cod': data.cod.toString(),
      'groups': data.idGrup //FK

pass the data and generate the error:
The ‘groups’ field does not have a default value
The ‘company’ field does not have a default value

const result = await knex('products')
      'name': data.name,
      'price': data.price,
      'company': ids.idCompany,
      'on_off': data.onOff,
      'cod': data.cod.toString(),
      'groups': data.idGrup

To change this error you have to use the knex.

Another interesting thing is that strapi does not create foreign keys, but only a field with an int value and that field can receive anything as long as it is integer.
for example:
tebela company
id (PK)
name varchar

product table
id (PK)
name vahcar
company int (FK)