check repetition in one table and replicate to another

[mgn]

I have an appsheet application, right?
In this application I have a Registration table which, when a form is filled out, also sends some data to another table called Preliminary, where several lines are inserted, depending on one of the form fields in the Registration table, for example: the Quantity_Sites field, of type Number, in the Registration table, is filled in the form with the number 10, then when the form is saved, a line will be inserted in the Registration table but in the Preliminary table 10 new lines will be inserted with information from the Registration table. And an important point is that the ID of the Registration table is passed to the preliminary table for each new line inserted.

There is another field in the registration table form that is filled in before saving the form, this field is the Title and is of type Text.

What I want is that whenever new information is inserted in the Registration table, it is checked whether the Title is the same as one already existing in the table and then the id of the new fields that will be inserted in the Preliminary table are exchanged for the id already existing in the Registration table.

[lynchk21]

I got a little confused on the last part - any clarification or screenshots you could provide to help me underdstand?