Ukrainians often use the phrase "на протязі" without realizing the mistake. In reality, this expression is a calque from Russian and is quite widespread. It is an incorrect translation of the phrase "на протяжении," although it literally translates the Russian term "на сквозняке."
If we want to express the duration of time, it is better to use "протягом" or even better – "впродовж". "На протязі" is used in a different context: a draft refers to a flow of air, and to be "на протязі" means to be in that flow, in a place that is being aired out.
Incorrect: I will complete this task на протязі the day.
Correct: I will complete this task протягом/впродовж the day.
Correct: If you sit много на протязі – you can get sick.
Incorrect: We traveled around Ukraine на протязі summer.
Correct: We traveled around Ukraine протягом summer/влітку.