Error when using openvidu-java-client in gradle project

Hi,

I have followed the tutorial for ip-camera and it works well. My problem is that the tutorial is made with maven and I need it to work with gradle. I have tried to migrate the project to gradle but I got this error

Errors occurred while build effective model from /Users/mbo/.gradle/caches/modules-2/files-2.1/io.openvidu/openvidu-java-client/2.20.0/d1b4db33036a286e7eeec5ece212c07e74417e60/openvidu-java-client-2.20.0.pom:
    'dependencies.dependency.version' for com.google.code.gson:gson:jar must be a valid version but is '${version.gson}'. in io.openvidu:openvidu-java-client:2.20.0
    'dependencies.dependency.version' for org.slf4j:slf4j-api:jar must be a valid version but is '${version.slf4j}'. in io.openvidu:openvidu-java-client:2.20.0

Can you tell me how to fix this issue please ?
Here is my build.gradle file

plugins {
    id 'java'
    id 'org.springframework.boot' version '2.6.0'
    id 'io.spring.dependency-management' version '1.0.11.RELEASE'
}

group 'io.openvidu'
version '2.20.0'

repositories {
    mavenCentral()
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'org.springframework.boot:spring-boot-starter-thymeleaf'
    implementation 'io.openvidu:openvidu-java-client:2.20.0'
    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.7.0'
    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.7.0'
}

test {
    useJUnitPlatform()
}