Odoo v14 Merge product variants

Hello, we have some product templates duplicated in Odoo. Both product templates have the same internal reference but different product variants, we need to merge the products variants in a single product template.

Example:
- Product Template 1:
* Product Variant 1: Size S, Color: Blue
* Product Variant 2: Size M, Color: Blue

- Product Template 2:
* Product Variant 1: Size L, Color: Blue
* Product Variant 2: Size XL, Color: Blue

After merge process we expect to have only 1 product template with all the variants on it.
- Product Template:
* Product Variant 1: Size S, Color: Blue
* Product Variant 2: Size M, Color: Blue
* Product Variant 3: Size L, Color: Blue
* Product Variant 4: Size XL, Color: Blue