You can also use a script like the one below to retrieve information from emails in a shared mailbox without using the "Retrieve email messages from Outlook" action.
- %SharedMailboxAddress%: Shared mailbox address
Dim olApp 'Outlook.Application
Dim rp 'Outlook.Recipient
Dim itm 'Outlook.MailItem
Dim ary(), i
Const olFolderInbox = 6
Set olApp = GetObject(, "Outlook.Application")
Set rp = olApp.Session.CreateRecipient("%SharedMailboxAddress%")
rp.Resolve
If rp.Resolved Then
With olApp.Session.GetSharedDefaultFolder(rp, olFolderInbox)
ReDim ary(.Items.Count - 1)
For i = 1 To .Items.Count
ary(i - 1) = .Items(i).Subject & vbTab & .Items(i).SenderName
Next
End With
WScript.Echo Join(ary, vbCrLf)
End If
Here is a sample flow:

SET DataTable TO { ^['Subject', 'SenderName'] }
SET SharedMailboxAddress TO $'''shared@***.onmicrosoft.com'''
Outlook.Launch Instance=> OutlookInstance
@@copilotGeneratedAction: 'False'
Scripting.RunVBScript.RunVBScript VBScriptCode: $'''Dim olApp \'Outlook.Application
Dim rp \'Outlook.Recipient
Dim itm \'Outlook.MailItem
Dim ary(), i
Const olFolderInbox = 6
Set olApp = GetObject(, \"Outlook.Application\")
Set rp = olApp.Session.CreateRecipient(\"%SharedMailboxAddress%\")
rp.Resolve
If rp.Resolved Then
With olApp.Session.GetSharedDefaultFolder(rp, olFolderInbox)
ReDim ary(.Items.Count - 1)
For i = 1 To .Items.Count
ary(i - 1) = .Items(i).Subject & vbTab & .Items(i).SenderName
Next
End With
WScript.Echo Join(ary, vbCrLf)
End If''' ScriptOutput=> VBScriptOutput
Text.SplitText.Split Text: VBScriptOutput.Trimmed StandardDelimiter: Text.StandardDelimiter.NewLine DelimiterTimes: 1 Result=> Lines
LOOP FOREACH CurrentItem IN Lines
Text.SplitText.Split Text: CurrentItem StandardDelimiter: Text.StandardDelimiter.Tab DelimiterTimes: 1 Result=> Columns
Variables.AddRowToDataTable.AppendRowToDataTable DataTable: DataTable RowToAdd: [Columns[0], Columns[1]]
END