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Navigate to Customization > SuiteBundler > Search and Install Bundles.
Search for [STA] INFlow or Bundle ID: 301105. Click the bundle name.
Click Install.
On the installation page, select the following preferences on the Preview Bundle Install page:
Custom Fields
[STA] Company EDI {custrecord_sta_einvoicing_payee_edi} > Replace Existing Object
Custom Records
E-Document Templates > Merge Data
Inbound E-Document Validation Plugin > Merge Data
E-Document Package > Merge Data
Custom Lists
[STA] EU Country > Merge Data