Exchange Online with OAuth2.0 I got Error

Question

Im trying to make Receiving emails from Exchange Online with OAuth2.0.
Now Im trying to get AuthToken but I Got error below.
May I help me about this Error.

Cannot find an overload for "AcquireTokenByUsernamePassword" and the argument count: "3".
At line:17 char:5

• $PublicClientApplication.AcquireTokenByUsernamePassword($scopes, ...
• ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
• CategoryInfo : NotSpecified: (:) [], MethodException
• FullyQualifiedErrorId : MethodCountCouldNotFindBest

My Script:
$ClientId = "____________________________________"
$TenantId = "____________________________________"
$UserName = '____________@_______.onmicrosoft.com'
$Pass = '_______'

[string]$Scopes = @("https://outlook.office365.com/IMAP.AccessAsUser.All","https://outlook.office365.com/SMTP.Send")  
$securePass = ConvertTo-SecureString $Pass -AsPlainText -Force  
$Options = [Microsoft.Identity.Client.PublicClientApplicationOptions]::new()  
$Options.ClientId = $ClientID  
$Options.TenantId = $TenantID  
# $Options.RedirectUri = $RedirectUri  

$PublicClientApplication = [Microsoft.Identity.Client.PublicClientApplicationBuilder]::CreateWithApplicationOptions($Options).Build()  

$AuthToken = $PublicClientApplication.AcquireTokenByUsernamePassword($scopes, $UserName, $securePass).ExecuteAsync()  

Answer 1

The AcquireTokenByUsernamePassword method is expecting an IEnumerable for the scopes so i believe that's what is complaining about I would suggest you try

 $Scopes = New-Object System.Collections.Generic.List[string]
 $Scopes.Add("https://outlook.office365.com/IMAP.AccessAsUser.All")
 $Scopes.Add("https://outlook.office365.com/SMTP.Send")
 $securePass = ConvertTo-SecureString $Pass -AsPlainText -Force
 $Options = [Microsoft.Identity.Client.PublicClientApplicationOptions]::new()
 $Options.ClientId = $ClientID
 $Options.TenantId = $TenantID
 # $Options.RedirectUri = $RedirectUri

 $PublicClientApplication = [Microsoft.Identity.Client.PublicClientApplicationBuilder]::CreateWithApplicationOptions($Options).Build()
 $AuthToken = $PublicClientApplication.AcquireTokenByUsernamePassword($Scopes, $UserName, $securePass).ExecuteAsync().GetAwaiter().GetResult()

which works okay for me