connection error password authentication failed for user postgres postgreSQL Server

How to give postgres user password in node js project to connect to postgreSQL 15 server pgAdmin 4 posgres user password postgres database How to fix the connection error error: password authentication failed for user "postgres" at Parser.parseErrorMessage (E:studynode_modulespg-protocoldistparser.js:287:98) at Parser.handlePacket (E:studynode_modulespg-protocoldistparser.js:126:29) at Parser.parse (E:studynode_modulespg-protocoldistparser.js:39:38) at Socket.anonymous (E:studynode_modulespg-protocoldistindex.js:11:42) at Socket.emit (events.js:400:28) at addChunk (internal/streams/readable.js:293:12) at readableAddChunk (internal/streams/readable.js:267:9) at Socket.Readable.push (internal/streams/readable.js:206:10) at TCP.onStreamRead (internal/stream_base_commons.js:188:23) How to solve connection error error: database "databasename" does not exist at Parser.parseErrorMessage (E:studynode_modulespg-protocoldistparser.js:287:98) at Parser.handlePacket (E:studynode_modulespg-protocoldistparser.js:126:29) at Parser.parse (E:studynode_modulespg-protocoldistparser.js:39:38) at Socket.anonymous (E:studynode_modulespg-protocoldistindex.js:11:42) at Socket.emit (events.js:400:28) at addChunk (internal/streams/readable.js:293:12) at readableAddChunk (internal/streams/readable.js:267:9) at Socket.Readable.push (internal/streams/readable.js:206:10) at TCP.onStreamRead (internal/stream_base_commons.js:188:23)