Where exactly is Saraswati River as per the mythology?

I’ve read about the three rivers- Ganga, Yamuna & Saraswati merging in the Triveni Sangam in Prayagraj. But recently I came across an article which described the supposed geographical location of Saraswati River. It mentions that the river started in Himachal Pradesh & crossed Haryana & finally through Rajasthan. According to this, the route of River Saraswati doesn’t pass through the Triveni Sangam. Do we have any other description about the river which can negate this claim?