Cannot upload zip file containing lambda function

[bifocalpirate]

I am trying to upload a lambda function contained in a 3.9mb zip file. It's a nodejs project (with accompanying node_modules). Uploads and works fine when uploaded to AWS Lambda.

The frontend returns

NetworkError when attempting to fetch resource.

The backend returns

localstack-explorer  | {"level":50,"time":1786596031234,"pid":1,"hostname":"3490159064bb","err":{"type":"FastifyError","message":"Request body is too large","stack":"FastifyError: Request body is too large\n    at rawBody (/app/localstack-explorer/node_modules/fastify/lib/content-type-parser.js:239:10)\n    at ContentTypeParser.run (/app/localstack-explorer/node_modules/fastify/lib/content-type-parser.js:203:5)\n    at Object.handleRequest (/app/localstack-explorer/node_modules/fastify/lib/handle-request.js:60:46)\n    at runPreParsing (/app/localstack-explorer/node_modules/fastify/lib/route.js:651:19)\n    at next (/app/localstack-explorer/node_modules/fastify/lib/hooks.js:236:9)\n    at handleResolve (/app/localstack-explorer/node_modules/fastify/lib/hooks.js:253:7)","code":"FST_ERR_CTP_BODY_TOO_LARGE","name":"FastifyError","statusCode":413},"msg":"Request body is too large"}
localstack-explorer  | {"level":30,"time":1786596031235,"pid":1,"hostname":"3490159064bb","reqId":"req-tm","res":{"statusCode":500},"responseTime":0.5845029354095459,"msg":"request completed"}

I am also using the docker image.