getCertificate() throws URI must be a string or UriInterface in staging mode.

[pelister]

testing with staging mode, creation and validation of the order passed, but at the stage of issuing certificate it throws the error - URI must be a string or UriInterface

pls help

[pelister]

before calling $certificate = $client->getCertificate($order);, I am printing the order object

and here is the order object

Afosto\Acme\Data\Order Object
(
    [url:protected] => https://acme-staging-v02.api.letsencrypt.org/acme/order/157323023/28099655983
    [status:protected] => ready
    [expiresAt:protected] => DateTime Object
        (
            [date] => 2025-10-30 17:51:18.000000
            [timezone_type] => 3
            [timezone] => Asia/Kolkata
        )

    [identifiers:protected] => Array
        (
            [0] => Array
                (
                    [type] => dns
                    [value] => he****.com
                )

            [1] => Array
                (
                    [type] => dns
                    [value] => www.he**.com
                )

        )

    [authorizations:protected] => Array
        (
            [0] => https://acme-staging-v02.api.letsencrypt.org/acme/authz/157323023/19863741633
            [1] => https://acme-staging-v02.api.letsencrypt.org/acme/authz/157323023/19863741643
        )

    [finalizeURL:protected] => https://acme-staging-v02.api.letsencrypt.org/acme/finalize/157323023/28099655983
    [domains:protected] => Array
        (
            [0] => he**.com
            [1] => www.he**.com
        )

)

it fails exactly while calling $certificate = $client->getCertificate($order)