How does one complete the Eid prayer if they join the Imam during the Tashahhud or in the second Rak'ah?

Scholars have differed regarding what constitutes catching the congregation in the Eid prayer. So, whoever says that it is caught by the opening takbir (takbirat al-ihram) before the Imam's taslim (salutation) has caught the prayer, and it is obligatory for you to complete the remaining two rak'ahs with their extra takbirs. And whoever says that it is caught by one rak'ah before the taslim, then the Eid prayer in congregation has been missed, and it is prescribed for you to pray it individually in its full form and with its extra takbirs. The extra takbirs are a sunnah; so, if you intentionally or unintentionally omit them, there is no blame upon you.