How to connect to database from a docker container inside a droplet?

I have just created a droplet and installed Docker to run an openjdk image with a springboot app but i get this error when trying to connect to my database

java.sql.SQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
        at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:110) ~[mysql-connector-java-8.0.28.jar!/:8.0.28]
        at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97) ~[mysql-connector-java-8.0.28.jar!/:8.0.28]
        at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89) ~[mysql-connector-java-8.0.28.jar!/:8.0.28]
        at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63) ~[mysql-connector-java-8.0.28.jar!/:8.0.28]
        at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:73) ~[mysql-connector-java-8.0.28.jar!/:8.0.28]
        at com.mysql.cj.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:899) ~[mysql-connector-java-8.0.28.jar!/:8.0.28]
        at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:824) ~[mysql-connector-java-8.0.28.jar!/:8.0.28]
        at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:449) ~[mysql-connector-java-8.0.28.jar!/:8.0.28]
        at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:242) ~[mysql-connector-java-8.0.28.jar!/:8.0.28]
        at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:198) ~[mysql-connector-java-8.0.28.jar!/:8.0.28]
        at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138) ~[HikariCP-4.0.3.jar!/:na]
        at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:364) ~[HikariCP-4.0.3.jar!/:na]
        at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:206) ~[HikariCP-4.0.3.jar!/:na]
        at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:476) ~[HikariCP-4.0.3.jar!/:na]
        at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:561) ~[HikariCP-4.0.3.jar!/:na]
        at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115) ~[HikariCP-4.0.3.jar!/:na]
        at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-4.0.3.jar!/:na]
        at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-5.6.8.Final.jar!/:5.6.8.Final]
        at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:181) ~[hibernate-core-5.6.8.Final.jar!/:5.6.8.Final]

the droplet is alredy on the Trusted sources of the database and is on the same network as the database