Unless you are paying cash, your offer will be contingent on obtaining financing. Early in the search stage, your Atlas broker will assist in getting you pre-qualified for a mortgage if financing is required. This is an important step, as many sellers will not allow showings to prospective buyers without evidenced pre-approval of capital.
If you are pre-approved but fail to actually receive loan commitment, there are a few options. One option is to walk away from the transaction. The second is to renegotiate the contract price to the appraised value. The third is for the seller to pay the difference. Your options can be limited depending on the type of loan you choose.