Get-AdfsCertificate is accessible with the help of adfs module. To install adfs on your system please refer to this adfs.
Synopsis
Retrieves the certificates from AD FS.
Description
The Get-AdfsCertificate cmdlet retrieves the certificates that Active Directory Federation Services (AD FS) uses for token signing, token decrypting, card signing, and securing service communications.
Parameters
-CertificateType
Specifies the type of the certificate to retrieve. The acceptable values for this parameter are:
    -- Infocard-Signing 
    -- Service-Communications
    -- Token-Encryption
    -- Token-Signing
    Required?                    false
    Position?                    1
    Default value                none
    Accept pipeline input?       false
    Accept wildcard characters?  false
-Thumbprint <String[]>
    Specifies the thumbprint of the certificate to retrieve.
    Required?                    true
    Position?                    1
    Default value                none
    Accept pipeline input?       false
    Accept wildcard characters?  falseSyntax
Get-AdfsCertificate [[-CertificateType] <String[]>] [<CommonParameters>]
Get- AdfsCertificate [-Thumbprint] <String[]> [<CommonParameters>]
Notes
You can use the Get-AdfsCertificate cmdlet without any parameters to get all the certificates.
———————-Example 1 ———————-
Get the token-signing certificates
PS C:>Get-AdfsCertificate -CertificateType “Token-Signing”
This command retrieves the token-signing certificates for AD FS.
You can check the Version, CommandType and Source of this cmdlet by giving below command.
Get-Command Get-AdfsCertificate
You can also read about
- Add-AdfsCertificate
 - Remove-AdfsCertificate
 - Set-AdfsCertificate
 - Update-AdfsCertificate
 

