If you have not already done so, you need to create a client profile on Upwork. This IS NOT A NEW UPWORK ACCOUNT.
You will only have one Upwork account. You will only have one email address, username, and password.
You will use your existing Upwork account to add a "client profile."
Then using your client profile, you will post a job listing asking for a sales manager, describing exactly what it is you intend this person to do. You will probably want to make this an hourly position, and then set a reasonable limit to the number of hours per week that this sales manager works. Perhaps 4 hours per week.
re: "I'm receice 30 propositions. All of them have hour rate. Will it's normal if I offer work for percent of order's price?"
They all are hourly rate proposals because your job posting was an hourly rate posting.
You were offered two option - hourly or fixed price - and you left the default option active.
Is it normal to pay via commission only on Upwork?
No, the site is not really set up for that. You could offer bonuses based on sales, in addition to paying hourly rates.
I'm sure some clients have managed sales-percentage deals using fixed-price contracts, but I am not sure if doing so fits into the site's intended use, or even if doing something like that is in keeping with the site ToS.
So Preston - are you saying that an hourly job is the default if a client doesn't pay attention filling up the job form? Because that would explain to me why I see so many hourly-posted jobs asking for a fixed rate. I thought it was some weird agenda, but it seems then it's maybe just laziness or inability to read the instructions?
I must say though that I really like the new-look Upwork. (No, really I must say that.)
re: "are you saying that an hourly job is the default if a client doesn't pay attention filling up the job form?"
There are two options.
The hourly pay method is pre-selected.
I actually think hourly rates are more civilized and entail less drama and less complications. As a client, I prefer using hourly rates.
Hourly rates definitely can be more expensive to use. But I think hourly rates with quality contractors yield higher-quality results.
Obviously that depends on the type of job and it depends on the type of contractor. A client with little experience with a certain job skill will want to hire multiple contractors to compare their relative cost and value.