iphone – downgrade ios 14 to 13.7 issues shsh blob

when i am trying to downgrade ios 14 to 13.7 it dose not work with future store show to me error in the photo below .i already saved my shsh blobs of ios 13.7 my iphone 7+ not jailbroken .. does there another method to downgrade with shsh blobs if future store issue not fixed thanks advance enter image description here