1)- How to attach expenses to activities of a project already registered on projeqtor ?

Expenses are "attached" to project (select project on expense) but they cannot be attached to Activity.
You can "link" expense to the activity, but there is no way to sum expenses of one activity.

2)- Can we reset the scheduled dates? If it's possible, how to do it?

I don't understand your question.
What do you mean by "reset the scheduled dates" ?

Hello,
I'm apologise for the dely, I mean, is it possible to reinitialize the dates?
I have a second question if you allow, nothing happens when I click on the icon "export schedule in PDF"! Is it a problem of updating or something else?

I'm apologise for the dely, I mean, is it possible to reinitialize the dates?

Which dates ?

I have a second question if you allow, nothing happens when I click on the icon "export schedule in PDF"! Is it a problem of updating or something else?

It should word...
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