I cannot generate API security tokens in the Team Center
I can see this error in the Enterprise Manager logs
The apm_secure_store table was missing completely.
This was after an upgrade from 10.5 to 10.7 but the table is not created/altered in 10.7 so it would appear the table has been missing since installation.
APM 10.7, upgrade from 10.5. Oracle database
You can find the scripts to create the table in the Enterprise Manager installation.
Under EM_HOME/install/oracle/database-scripts, you can find the script createtables-oracle-xx.x.x.x.sql, for example createtables-oracle-10.5.0.0.sql
Details on creating/managing the database schema manually