Extremely confused about the calculation of the life path number

[Sunshine111]

I am extremely confused about the calculation of the life path number because different "numerologists" calculate this in two different ways.

For example, the first group calculates the life path number adding all numbers of date of birth in a straight line without reducing the day of birth, month or year in a single digit number first.

So, if the date of birth is 14.11.2019 , the way the life path number is calculated is, 1+4+1+1+2+0+1+9.

The way of calculcation of the second group of numerologists now is to reduce the number of the day, month and year into 1 single digit number then, add these numbers.

So their way of calculation of the life path number for the above date of birth 14.11.2019 will be, 5(1+4)+2(1+1)+3(2+0+1+9).

The two different ways of calculation now, give me two completely different numbers as my life path number, reason why of my extreme confusion.

What is the correct way of calculation of life path and is it best another to go with the numbers they can identify with and feel that they represent them?.

For example, if based on the first calculation, my life path number is 6 , whereas with the second one is 5, cannot identify with 6 but can identify with 5, is it not best to choose the way of calculation that results in the numbers that reflect/represent who I am and can identify with?.

And, who exactly decided or decides what "the correct way" of calculation is?.

Is their ancient book that another can consult instead of current or recent in time numerologists?.