How to upgrade, downgrade, or change their subscription

[karta012719]

How to upgrade, downgrade, or change their subscription

[dhirajved]

Note : read first 5 proration mode for upgrade, downgrade for subscription .

for more you can refer this doc
https://developer.android.com/google/play/billing/subscriptions#upgrade-downgrade

use this code for upgrade, downgrade for subscription

BillingFlowParams billingFlowParams = BillingFlowParams.newBuilder()
    .setProductDetailsParamsList(
        ImmuableList.of(
            ProductDetailsParams.newBuilder()
                // fetched via queryProductDetailsAsync
                .setProductDetails(productDetails)
                // offerToken can be found in
                // ProductDetails=>SubscriptionOfferDetails
                .setOfferToken(offerToken)
                .build()))
    .setSubscriptionUpdateParams(
        SubscriptionUpdateParams.newBuilder()
            // purchaseToken can be found in Purchase#getPurchaseToken
            .setOldSkuPurchaseToken("old_purchase_token")
            .setReplaceSkusProrationMode(ProrationMode.DEFERRED)
            .build())
    .build();

BillingResult billingResult = billingClient.launchBillingFlow(activity, billingFlowParams);