How to insert a function into a templated query string?

Question

PostgreSQL

How to insert a function into a templated query string?
The created field is of type timezone. I want to convert the source data to this type using the postgre's TO_TIMESTAMP() function .
How to do it?

INSERT INTO data.source(created, created_utc) VALUES($1, $2)

If I insert the function directly into the values, then this error:

error: invalid input syntax for type timestamp with time zone: "TO_TIMESTAMP('1581569438')"

If I do this:

INSERT INTO data.source(created, created_utc) VALUES(TO_TIMESTAMP('$1'), TO_TIMESTAMP('$2'))

That error is the following:

duplicate key value violates unique constraint "source_pkey"

Answer 1

The second option is ok. They also write to you that the uniqueness is violated - there are already such (such) values ​​in the table. For which fields do you have the source_pkey constraint (this, apparently, is the primary key)?