Login to your Salesforce org where the package is installed.
Check for Lookup between Plaid Payment and Source object. If there is no lookup, create a lookup relationship between them.
Create a Button named as Initiate Payment on Supplier Invoice(Source object).
Action Type:- Lightning Component
Height:- 450px
Lightning Component: PaymentTransferAura
Label: Initiate Payment
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Drag Action Element from the Left-side list of Elements and call the Apex Class bankconnect_InvocablePaymentInitiationProcess Class as shown below:-
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Congratulations! You have successfully installed Payment Transfer Application.