Can the use of the invitation code be terminated?

It can be terminated. You can perform the operation through the following path:
On the elink management console, click [Marketing Center] - [Invitation Codes], find the invitation codes of the target batch, and click [Invalidate Immediately]. This will invalidate the unused invitation codes in this batch, while the previously used invitation codes will remain unaffected. Currently, batch invalidation and single invitation code invalidation are supported. The operations are as follows:

1. For batch invalidation, select the target batch and click "Invalidate".

2. For single invalidation, click "Usage Records" of the target batch, select the invitation code to be invalidated, and click "Void".