If you do not have your backup phrase:
If you do not have your backup phrase, then unfortunately you have lost your wallet and all funds in the wallet. For security, 12 word backup phrases are not stored on BitPay servers, so BitPay cannot recover funds for you.
If you still have your backup phrase:
Open the app and go to the gear icon in the top right corner. Then scroll down and choose Add Wallet. Then choose Import Wallet and the Recovery Phrase tab. Type out your 12 word recovery phrase and click Import to restore your funds.
If you have a file or text backup:
Open the app and go to Settings (the gear icon) in the top right corner. Then scroll down and choose Add Wallet. Next, choose Import Wallet and the File/Text tab.
* File format: from Windows, Linux, Mac, and Chrome App (previous format, the Chrome app is no longer supported). Upload the file.
* Text format: from mobile devices. Paste the json format as plain-text.
Note: All File/Text backups have a password. You will need to enter this password in order to restore your wallet.