The PRO limit is a total limit. If you have multiple accounts linked the total limit is valid for all linked accounts together and not per account.
Once it is reached you will not be able to add more trades.
1. summarize some of your existing transactions manually e.g. in Excel (in case of a trade only the same trade pair and time stamp), delete the single transactions and set a start date to avoid re-import of the single transactions.
2. or upgrade to EXPERT S or any other plan as described here: Reached Trade Limit - upgrade how and why?