You must report the full amount you pay to the contractor on a 1099-NEC.
Are you saying that other people are paying the contractor on your behalf? Or are you saying other people have given you money to help pay the contractor?
Since this is a schedule E, I will assume this is repairs to a rental property for sake of argument. If other people paid the contractor, then you issue the 1099 for what you actually paid, and only the amount you paid is a deductible rental expense. For example, if the repairs cost $1000 but you only paid $800, then you issue the 1099 for $800 and your expense is $800, not $1000.
If other people paid you, and you paid the contractor the entire amount, then you issue the 1099 for whatever you paid and whatever you paid is the rental expense. But, we then have to ask, were the third party payments to you reportable as income on schedule E, or were they non-taxable gifts. I think that depends on the business relationship, if any. Suppose the property is a historic landmark that was damaged in a storm. If you get a grant from the city or a historic preservation organization to help with repairs, that is taxable to you because you had a business relationship with the payor. Likewise if your tenants helped pay, because of the business relationship. But if you set up a gofundme to help repair the historic property, and the donations were freely given by strangers who had no interest in the property, then those might be non-taxable gifts.
